Faded Gibson finish

[MoonBassAlpha]

My 74 SG Special which was a lovely deep red wine colour in its youth is now entirely brown. Is this because the clear lacquer has turned yellow, or the stain itself has faded?

[Bigguy2017]

It's usually because the red stain has faded; it's the same with burst colours - red is the first to go.

[Maude]

Colours appear as colours to us due to which frequencies of the visable light spectrum they absorb. Red has the longest wavelength through to violet which has the shortest. If a material absorbs the longer wavelengths and reflects only the shortest it will appear red (turn the light off so there's none to reflect and everything loses its colour). 

For something to appear red it has to absorb all the other wavelengths of light, getting progressively shorter as you move up the spectrum. Shorter wavelengths have more energy and destroy the pigments in paint quicker than the less energetic long wavelengths, causing red pigments to lose their 'colour' the quickest. 

[MoonBassAlpha]

Thanks chaps, kinda what I thought initially, but then had a moment of doubt. I just hate keeping guitars in a case as it's yet another barrier to picking up and playing, so I guess it's the price you pay with older instruments.