const vec3 color_1 = vec3( ... );
const vec3 color_1 = vec3( ... );
float z = f(uv);
float r = ...;
float s = ...;
float b = 1. - lhr(r, r + s, z);
color = lr(color_1, color_1, b);

const vec3 color_1 = vec3( ... );
const vec3 color_1 = vec3( ... );
float z = f(uv);
float r = ...;
float s = ...;
float b = 1. - lhr(r, r + s, z);
color = lr(color_1, color_1, b);