@usamor - In general, I agree with you but its more complicated because lots of clouds (stratus and newly formed/forming cumulus) tend to be quite uniform in appearance and that appearance depends strongly on whats behind those clouds. They can be bright when backlit by the sun. They can appear grey against a blue sky or blue against the apparent white of a more well formed cumulus.
A more well formed cumulus will both reflect light and block light. When looking away from the sun it is as you say and you tend to see a brighter center of a cloud ‘puff’ with a darker surround but when seen against the sun its the direct opposite - a dark center with a silver lining. And of course this varies all dependent on your position and the clouds position and the suns position.
I hope that ray tracing might be useful to improve this situation but right now Id be happy if they just improve the colors. Start every cloud at a dim blue grey but let cumulus get brighter on their faces as they grow and darker slighter higher in hue blue in their shadows also as they grow.
just no more ashy yellow. its getting old.