Red cars seem to fade far more than any other colour, even when not that old. You see loads of pink roofed and bonneted cars in red (particularly Royal Mail vans).

I was wondering if there is any particular reason why? Is there something about the red pigment that makes it particularly susceptible to UV damage??

iirc it does have something to do with the pigment. Red paint is often softer and more prone to minor scratches too.

I think that’s it, cheap water based paint, UV and cheap pigments. I’m sure someone cleverer than me will be along with light frequency and wave length explanation.

Red paint used to oxidise.Mop it up it looks a treat. Next day back to dull again.
Shouldn’t happen in the age of base coat and lacquer.
Edit.non lacquered metallics used to go dull as well due to the particles oxidising. That really lead to cars being lacquered. We used to have problems with some yellows as well.

Had this discussion with a car dealer the other week (see free car thread!)…

He was saying often it’s to do with the type of paint used. Was talking about oil based and water based paints. He claimed the oil based paints are more susceptible to fading. No idea if it’s true – or whether red cars are more likely to use oil based paints for some reason than any other.

We just decided to be boring and stick with black.

Its because their stars burn more brightly than than those greyish silver wankspanna carriages.

It’s because red cars go faster, it wears the paint off quicker, like a space shuttle on re-entry, e.g. post vans.

It’s because anyone that buys a red car, obviously doesn’t have any pride in their vehicle – red cars look shit, even when new, so they don’t wash them and they fade. Simples 😉

My washing machine is silver, I’m very proud of that.

It’s because anyone that buys a red car, obviously doesn’t have any pride in their vehicle – red cars look shit, even when new, so they don’t wash them and they fade. Simples

My ancient Nissan Almera gets washed about twice a year. It’s still very red. I reckon a permanent thin covering of grime has provided some uv protection over the years.

Its because their stars burn more brightly than than those greyish silver wankspanna carriages.

How would you even notice if a grey car had faded?

eventually they go beige

Red is a fugitive colour, and is more affected by UV light, compared to blur. Yellow is next. Look at a colour advertising poster that’s been stuck up in a window for a while, pretty much all that’s left is the cyan and black, with a touch of magenta, and almost no yellow.
Darker reds, edging into maroon, burgundy, don’t fade so much because they have blue and black mixed in to achieve the darker colour.

@CountZero – great explanation, thanks!

It’s the doppler effect

@CountZero – great explanation, thanks!

Is it? Why do red cars fade? “Because they’re red”. Although we do have a bonus word “fugitive”, which we now have to look up. 🙂

Edit:

Fugitive pigments are impermanent pigments that lighten, darken, or otherwise change in appearance or physicality over time when exposed to certain environmental conditions,

So “ones that fade”

7 mins later: http://www.forgottenbooks.com/readbook_text/The_Chemistry_and_Physics_of_Dyeing_1000161343/299

still not a great deal further on from “because they do”.

Although oxidation seems on the list – as someone’s mentioned already.

From CHEMISTRY AND PHYSICS OF DYEING, ACTION OF LIGHT ON DYEING OPERATIONS

“Three theories have been put forward to explain the cause of this action. They are of an indirect nature, and may be briefly summarised as follows :

(1) The oxygen theory. ” The dyes under the influence of light interact with oxygen, and form colourless compounds.

Berthollet in 1792 came to the conclusion that oxygen combined with the colours, and made them pale.

The colour at the end of the exposure is, from this point of view, proportional to the resistance to this action.

(2) The ozone theory, ” ^The colours are decomposed or altered by the production of ozone (or hydrogen peroxide) in the fibre, chiefly by evaporation of moisture.

(3) Reduction theory .”The dye is reduced by cotton fibre, or directly by the action of light.

Experiments conducted in the presence of oxidising agents have given conflicting results. The presence of sodium hydrosulphite solution also gives varying results.

Whatever be the cause of the results obtained in the presence of oxidising, or reducing reagents, it is important to note that dyed fabrics always show an increased fastness against the action of light in vacuo. This effect is very marked.

Similar experiments with sensitive organic compounds are wanting. They should be of equal interest.

A typical example of this action may be seen when cotton dyed with Diamine Sky Blue B is placed in long glass tubes, which are subsequently exhausted by water suction to a pressure of 10 mm. (9 mm. of which are due to water vapour), and exposed for fourteen days to bright light. The shade remained absolutely unchanged. A comparison trial, which was exposed to the light side by side with the other one, but under ordinary conditions, had entirely lost its colour. The cotton was quite white.

The same blue cotton sealed in a tube in an atmosphere of oxygen gas lost its colour even more rapidly than the above comparison sample. On the other hand, the colour remained unaltered in an atmosphere of either hydrogen, carbon dioxide, sulphur dioxide, or coal gas. When exposed in nitrous oxide gas the effect produced was very similar to that noticed in the case of oxygen.

It is evident, therefore, that dyed samples in the absence of oxygen will not fade.

Berthollet in 1792 noticed that the fading action of colours seemed to be intensified in the presence of an alkali. In the same way an acid condition seems to retard the fading action.

The fact that the fading is intimately connected with the presence of oxygen may, therefore, be taken as established. It remains to trace the actual action which takes place. It has been noticed that the evaporation of water at ordinary temperatures leads to the formation of ozone in very small quantities .

The fading of the colours may, therefore, be due to the direct interaction between the ozone, or hydrogen peroxide so formed, from the oxygen in the air; colourless compounds of unknown composition being produced. The action seems also to be proportional to the moisture present at the time of the experiment.

Under the influence of the light vibrations the oxygen molecule may be more readily split up, and an action of the following order induced:

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Ooooh! teaser! Anyone a member of Forgotten Books? 🙂

Also, I seem to recall (as previous owner of a very faded red Golf Mk II) that the redness used to be maintained by use of lead based pigments, which were gradually phased out across the EU – with the Germans leading the way, hence a lot of red faded VWs while BL & PSA cars were still quite lustrous..

A level chemistry about a billion years ago taught me something something to do with red pigment absorbing more high energy (blue) light and atoms losing their electrons quicker (oxidising quicker) something something that’s probably it I wonder if she fancies me oh what did Dr Wooster just say electrons that’s it.

I like red cars and apart from a Metro in the mid 80s I’ve not had a problem with them fading. Mrs rocket’s fabulous Fiesta ST is very red indeed.

Orange is definitely the worse. A neighbour had a Focus ST in orange and although it looked ace when it was new it soon faded to a kind of apricot colour. Have also had bikes and bits in orange some have faded as soon as they went outdoors

Wierdly my Miss’ fiestsa is orange (not ST orange) and has hardly faded at all in 10 years, i polished and waxed it the other day [i]year[/i] convinced it must make a difference, but it hardly did (beyond looking freshly polished and waxed).

This is all a bit simpler if you just try and understand the nature of the underlying pigments. The three component colours of Red, Blue, Yellow all have a certain strength relative to each other when mined from their base elements.

Red is the strongest pigment – therefore to produce a satisfactory depth of hue any motor manufacturer uses less of it. Ergo, the paint is in layman’s terms “thinner”. Trouble is, that makes it less resistant to fade than the others. But the other advantage is that, by using less paint, the vehicle will have lower mass, which means it will accelerate quicker when compared to other vehicles of equivalent spec. Not much, it’s only a few kg, but it will get there faster. Top speed won’t be affected though, obviously.

Hence – red cars are faster! I mean, why do you think Ferrari use it as their primary (pun intended) colour? It’s not just a weak attempt at entering the Chinese market!

My ancient Nissan Almera gets washed about twice a year. It’s still very red. I reckon a permanent thin covering of grime has provided some uv protection over the years.

That’s Almera’s for you. Chuck Norris of the car world.

The answer is up there pretty much. When people used to use inorganic lead containing pigment it was less of an issue. Same for chromate yellows.

Strong primary colours typically rely on organic colour pigments. These are normally aromatic in nature. They are less stable in UV light than inorganic pigments so will degrade faster. Black, white, metallic silvers can still use inorganic pigments (carbon, TiO2, Mica).

Better resin systems will help. Putting in UV absorbers and blockers will help stabilize your pigments as will good resin choice.

If I remember correctly from way back to my uni days and hybrid molecular orbital theory UV light excites an electron into a higher HOMO on its own which can then react with a LUMO on a neighboring molecule. Normally these molecules can’t react because the symmetry of the electron orbitals is wrong but having an electon in an excited state HOMO changes this. Same reaction that lets you create Vit D in sunshine.