This doesn't seem to be gamma correct, I just see / 255 and * 255.
sRGB is a nonlinear colour space and so you can't do linear operations in that space (because a^2 + b^2 isn't (a+b)^2 in general).
sRGB is a nonlinear colour space and so you can't do linear operations in that space (because a^2 + b^2 isn't (a+b)^2 in general).