well, hm. perhaps my RGB 33,33,38 is tiny a bit under what charts recommends , Unreal says deffuse reflectance / luminance for charcoal, dark fresh asphalt , dark rubber should be 0.02 . it's RGB 39 39 39 in 0-255 scale using typical luminance calculating formula for sRGB : 0.2126R + 0.7152G + 0.0722B. and srgb to linear…