vec3 sky_ColorSqrt = vec3(136.0, 172.0, 236.0) * 1.10 / 255.0;
vec3 skyColCustom = sky_ColorSqrt * sky_ColorSqrt;

vec3 skyMultRaw = vec3(SKY_MULT_R, SKY_MULT_G, SKY_MULT_B) * SKY_MULT_I / 255.0;
// Preserve the requested artistic tint without allowing a zero channel to
// erase atmospheric colours (notably every red at sunrise and sunset).
vec3 skyMult = mix(vec3(1.0), clamp(skyMultRaw, vec3(0.0), vec3(1.25)), 0.28);
