Thanks Cousin Ricky, that's a really good and useful distillation of the rgb vs.
srgb multiplication rules. I shall refer to it often. Those rules are easy to
forget :-(

> [jr wrote:]
> so, the "take away" is to not mix RGB types and 's' variants in the
> same scene ?

I don't think it causes any technical problems 'under the hood'-- I sometimes
mix the two 'flavors' in *object* colors, depending on...whim ;-) But as a
*general* rule, it is probably not a good idea to mix one flavor in LIGHTS with
another flavor on objects-- only because the resulting object colors would be
somewhat unexpected.  Consider the following combinations (while using
assumed_gamma 1.0):

the usual standard or typical way, no srgb:
light_source{ rgb <.3,.5,.7>}
object{... pigment{rgb <.5,.3,.1>}

vs.

light_source{ srgb <.3,.5,.7>} // srgb now
object{... pigment{rgb <.5,.3,.1>}

vs.

light_source{ srgb <.3,.5,.7>} // srgb now
object{... pigment{srgb <.5,.3,.1>} // srgb now

The object in each case will appear with a different brightness and a slightly
different hue...possibly not what you expect, given the unchanging triplet
values that you choose.

Personally, I like to use the 3rd combination...just a personal choice due to
familiarity with how colors in other graphics apps appear to me. No 'washed-out'
colors, in other words. I have never been very good at choosing plain rgb
triplets to get what I want.

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