Small four-cylinder pushrod engine built from 1951 to 2000 for the Austin A30 and A35, Morris Minor, Mini, Sprite and Midget, Metro and much else. Sources agree the block was green for roughly the first twenty years and black after that, but no factory paint code has been found, the green varied from batch to batch, and every changeover date is argued over.
Awaiting measurementC · Community consensusDisputedLast verified 2026-09-20
Awaiting measurement
Not yet measured. The patch will appear once a spectrophotometer reading is recorded.
Nearest RAL
RAL 6003
Nearest BS 381C
BS 381C 223 Middle Bronze Green
What is disputed
Two modern standards are quoted for this one colour and they are not the same green. Wikipedia and a Mini Forum member give BS 381C 223 Middle Bronze Green; Frost sells its BMC Green as RAL 6003, and a Mini Forum member reports the Mini specialist Guess-Works recommending RAL 6003 as well. Neither is traced to a BMC document in anything fetched here. Members of the Mini Forum and of the Morris Minor Owners Club board also insist the works shade drifted between batches and suppliers, so one reading off one engine will not settle it. The end date is disputed as well: see the black record.
No factory paint code for the engine colour was found in any source fetched. Finish is recorded as gloss because no source states a sheen. Retailer naming is loose and is not evidence of two factory colours: Rimmer Bros sells its brush-on version under manufacturer number CCEP3ABR while listing it as BMC Engine Green, and a Mini Forum member cites a Classic Car Colours tin labelled BMC Green EP3A. A Mini Forum member reports Riley Elf and Wolseley Hornet engines in a noticeably lighter shade; no second source was found for that. Sprite and Midget applicability is deliberately left out: the sources that describe a separate colour sequence for the 1275 Sprite and Midget could not be fetched.
Sources
community:Wikipedia, BMC A-series engine — States the engines were painted British Standard 381C 223 Middle Bronze Green until mid-1970, with replacement units in black.
forum:The Mini Forum, thread "Bmc Engine Green Paint Code" — Members name British Standard Middle Bronze Green (BS 223) as the commonest BMC engine colour, mention a darker variant on some engines, and separately report RAL 6003 and Land Rover Bronze Green as working substitutes.
forum:The Mini Forum, thread "Engine Colour" — A member states every Longbridge-built A-series was green until about 1970, and that the shade was never consistent between batches.
forum:PistonHeads Classic Minis, thread "engine color" — Members describe the early colour as a mid green close to Land Rover Bronze Green and point to Minispares part GAP410 as the current equivalent.
retailer: Frost, BMC Green Engine Enamel Paint 500ml (P800BMC) — Sells a brush-or-spray engine enamel named for BMC, rated to 170C, and gives its colour as RAL 6003.
retailer: Rimmer Bros, VHT Engine/Exhaust Paint BMC Engine Green 400ml (RX4154A) — Sells an aerosol named BMC Engine Green and advises a colour match test first because the car may not be the original shade.
History
2026-09-05 · Draft researched from public sources; unverified and unmeasured
2026-09-17 · Amazon UK offers added: Frost P800BMC (ASIN B0FD461H6P, sold by Frost Auto Restoration Techniques Ltd); Fascinating Finishes Ltd BMC & MOWOG green aerosol (B00AC20EDO) and 500ml tin (B096351BK2) added as matches. Verified on amazon.co.uk
2026-09-20 · Sources fetched again and checked against the record; published
Awaiting measurementC · Community consensusDisputedLast verified 2026-09-20
Awaiting measurement
Not yet measured. The patch will appear once a spectrophotometer reading is recorded.
What is disputed
The start of the black era is given as mid-1970 by Wikipedia and by a Mini Forum member, and as about 1972 by other Mini Forum members. None of them cites a document. This record uses the earlier claim; an engine built in 1971 could honestly be either.
Finish recorded as gloss because no source states a sheen; members describe surviving black engines as flat, which may be age rather than specification. Wikipedia says the black engines began as factory and dealer warranty replacement units, distributed mainly for failures of the wet crank primary gear in early Minis. Nothing is sold as a BMC engine black, and nothing needs to be: black has no shade to match, so the modern matches listed are general engine blacks chosen for their heat rating and availability.
Sources
community:Wikipedia, BMC A-series engine — Puts the end of the green finish at mid-1970 and says replacement units were black.
Awaiting measurementC · Community consensusDisputedLast verified 2026-09-20
Awaiting measurement
Not yet measured. The patch will appear once a spectrophotometer reading is recorded.
What is disputed
Whether this is a factory colour at all is unresolved. Morris Minor Owners Club board members who have stripped early Series II engines say the blue-grey is under the dirt and is not a fade; others argue it is weathered green. The same board carries a claim, attributed to Ray Newell's Original Morris Minor, that A-series engines were always green with only the shade varying. The book itself was not consulted for this draft, only owners quoting it.
Reported on saloons and travellers as well as light commercials in the same period, so on the evidence fetched the split is not simply car against van. No paint code, BS number or RAL number was found for it. The dates are the span club members describe, not a documented range.
Sources
forum:Morris Minor Owners Club board, thread "Engine colour." — Members report blue-grey engines on early Series II cars and on one 1957 car, and cite Ray Newell's book Original Morris Minor as recording the colour with no known reason for it.
Awaiting measurementC · Community consensusDisputedLast verified 2026-09-20
Awaiting measurement
Not yet measured. The patch will appear once a spectrophotometer reading is recorded.
What is disputed
The start date does not agree between sources: Wikipedia dates the A-Plus to 1980, while Mini Forum members date the coloured engines to 1982 or 1983. Owners also disagree about the shade, one describing a 1991 A-Plus engine as khaki or gold rather than yellow and being told it may be original, discoloured, or a reconditioned unit. No end date for the yellow was established.
Colour by capacity was a works identification aid as much as a finish, which is why it is worth recording even with no factory document behind it. Members report the same yellow on Metro 998 units. The 1992 end date is Wikipedia's production span for the 998 A-Plus, not a documented end for yellow paint.
Awaiting measurementC · Community consensusDisputedLast verified 2026-09-20
Awaiting measurement
Not yet measured. The patch will appear once a spectrophotometer reading is recorded.
What is disputed
As for the yellow 998: Wikipedia dates the A-Plus to 1980 and Mini Forum members date the coloured engines to 1982 or 1983. No source fetched gives a shade, a code or an end date for the red.
Members report the red on Longbridge-supplied assembly-line units. A red block in a car of this era is therefore not automatically a rebuilder's choice, which is the usual assumption.
A-series reconditioned exchange unit · 1959–2000 · block, gloss
Awaiting measurementC · Community consensusDisputedLast verified 2026-09-20
Awaiting measurement
Not yet measured. The patch will appear once a spectrophotometer reading is recorded.
What is disputed
Members of the same forum both assert and deny that gold identifies a factory-reconditioned Gold Seal exchange unit, the counter-claim being that reconditioned engines came in silver, gold, black, blue or whatever the shop had. Recorded because a gold A-series is common and is routinely mistaken for a previous owner's paint choice, not because the claim is settled.
This is a reconditioning finish rather than a production-line colour, so the year span is the life of the exchange scheme's engines, not a model year range. Anyone with a gold block should check the engine number prefix against a Gold Seal listing before treating the colour as evidence of anything.
Sources
forum:The Mini Forum, thread "Original Engine Colour" — A member attributes gold engines to Gold Seal reconditioned units; another reports two Metro 998 engines gold with no paint underneath.
forum:The Mini Forum, thread "Engine Colours..." — Members associate gold with reconditioned units, but one insists reconditioned engines were finished in whatever colour was to hand.
History
2026-09-05 · Draft researched from public sources; unverified and unmeasured
2026-09-20 · Sources fetched again and checked against the record; published
The A-series ran from 1951 to 2000, so its colour history is really three histories: the green years, the black years, and the A-Plus years when colour told you the capacity. None of the three is backed by a factory document that we have found. Every record on this page is graded C, which means owners' clubs, forums and Wikipedia agree with each other and nobody can point to a BMC drawing or paint specification. Where they disagree, the record says so.
What the factory did
For roughly the first twenty years the engine was green. Members of the Mini Forum, the Morris Minor Owners Club board and PistonHeads all describe the same thing under three names: BMC engine green, MOWOG green and Morris green. Wikipedia's A-series article gives the colour as British Standard 381C 223, Middle Bronze Green, and a Mini Forum member states the same standard with "100% certainty".
In practice it was never one colour. The point every source agrees on is that the shade wandered between batches and suppliers. Put two original engines side by side and you will rarely see the same green twice.
The engine was painted as a built-up unit. A Morris Minor Owners Club member describes everything being sprayed together, rocker cover included, with only the distributor and carburettor left off. That is why the rocker cover matches the block on an untouched engine, and why it usually survives better: it runs cooler. No source describes the head, sump or timing cover as a different colour, so they have no separate records here.
From the early 1970s the engine was black. Wikipedia dates the end of green to mid-1970, and says black began on factory and dealer warranty replacement units, sent out mainly for the primary gear failures that early Minis suffered.
With the A-Plus, colour started doing a job. Wikipedia says blocks and heads were colour coded by capacity, yellow for the 998 and red for the 1275, and forum members add that 1098 units stayed black. You could read the engine size from across a workshop.
What changed, and when
The changeover dates are the weakest part of the record. Green gave way to black in mid-1970 or in about 1972, depending on which thread you read, and nobody arguing either date cites a document. An engine built in 1971 could honestly be either.
The A-Plus dates are no firmer. Wikipedia puts the revision at 1980. Mini Forum members date the yellow and red engines to 1982 or 1983. Both spans are on the records above with the disagreement stated.
The blue-grey Morris Minor engine is the oldest puzzle. Club members report early Series II cars, and at least one 1957 car, with blue-grey engines on saloons and Travellers as well as vans. One owner was told by the BMC and BL heritage centre that his engine and rocker cover should be "a blue/green colour, not mowog green". Members point to Ray Newell's Original Morris Minor as showing the colour. We have not consulted the book ourselves, only owners quoting it.
What to buy
For a green engine there are three tins sold as BMC green, listed on the record above. They are not the same green. Frost states its BMC Green as RAL 6003. The others give no standard at all. RAL 6003 and BS 381C 223 are different colours, and neither has been traced to a BMC document, so nobody can tell you which is right. They can only tell you which is closer to the engine in front of you.
That makes the choice practical. If any original paint survives, take the engine's own colour as the reference, buy the nearest tin, and spray a test card before you commit. If nothing survives, remember that the factory shade varied, so a sound BMC green in the right family is as authentic as the evidence allows. You can compare every BMC green in the shop.
For a black engine, shade is no problem, because black has none to match. Choose on heat rating and on finish. The sources don't record whether the factory black was gloss or satin, and surviving engines look flat, which may be age.
All of these are one-pack engine enamels. They suit a block, a head and a rocker cover, and they will burn off a manifold. Engine enamel explains the ratings, and the preparation guide covers the work that decides whether the paint stays on.
Common mistakes
Assuming a gold block is somebody's idea of a custom finish. Forum members associate gold with factory reconditioned Gold Seal exchange units, in which case the colour is evidence about the engine's history and says nothing about a previous owner's taste. It is contested, and the engine number prefix settles it better than the paint does.
Buying "BMC green" and expecting one colour. The trade uses no single name or number for it. One supplier lists a tin as BMC Engine Green under a maker's code of CCEP3ABR, and a Mini Forum member has a tin from the same maker labelled BMC Green EP3A. That supplier's own listing tells buyers to test the colour match first, because the car may not be the original shade. Take that advice.
Treating a modern tin as a factory reference. A maker's choice of RAL 6003 tells you what that maker settled on. It tells you nothing about what Longbridge sprayed.
What is disputed
Three things, and the records state each one without choosing a side.
The first is the standard. BS 381C 223 Middle Bronze Green is set against RAL 6003, with no factory source behind either. Mini Forum members also mention Dark Bronze Green and Land Rover Bronze Green as matches for particular engines.
The second is the dates. Green ends in 1970 or 1972, and the A-Plus colours begin in 1980 or in 1982 to 1983.
The third is the blue-grey Minor engine. Owners who have degreased the block say it is an original factory finish. Others say it is green that has weathered. The heritage centre's "blue/green" makes a third position and settles nothing.
A Mini Forum member also reports Riley Elf and Wolseley Hornet engines in a noticeably lighter green. That is one report with nothing to corroborate it, so it has no record here.
Finding original paint on your own engine
The outside of the block is the worst place to look. Try the surfaces that ran cool and were shielded: under the dynamo or alternator bracket, behind the engine mounting plates, the underside of the rocker cover flange, and the back face of the block where the gearbox meets it. Degrease before judging anything. A-series green under fifty years of oil reads as brown, or as the blue-grey argued over above.
Look for layers. Several owners report paint over paint, which usually means a rebuild and not a change of mind at the factory. A single coat straight onto the casting, with overspray on fasteners the factory wouldn't have masked, is a better sign of originality than a tidy finish.
Then photograph it in daylight against something of known colour and, better still, have it measured. A spectrophotometer reading from an unfaded original would be worth more than everything else on this page, and nobody has taken one yet. If you have an engine that could settle any of this, tell us.
Every record above has a correction link. Applied corrections are logged on the record and on the changelog with their source and date.