when it comes to computer colors, even RGB values can be different. depending on OS or browser.

colors made with 0, 3, 6, 9, C, are supposted to be the same on ALL browsers.

003300 should be virtually identical when viewed on but
103310 could be surprizingly differnt!

Pantone is another standare (used by print media,and some programs like photo shop can calibrate your monitor to give 'pantone value' colors.

these various standards correct the various names/ideas about what color is what
Red--even 'true red' can be very subjective! just as (as has been discussed) A or middle C is subjective.. is the value for C 440 H? or some other number?) you can get an idea even when slightly out of tune, but music definately sounds better when there is a commonly agreed on value!

my other obsession