Night mode in iPhone/iPad?

Question

iPhone

Please tell me how to make a night mode in the application? So that everything is red, as, for example, in Solar Walk

Answer 1

If the application uses OpenGL, then it will be enough to write a wrapper function for glColor (well, for glMaterial and glLight, if they are used) like this:
void SetColor(float R, float G, float B, float A)
{
  if (!NightMode)
    glColor4f(R, G, B, A);
  else
    glColor4f(R, 0, 0 A);
}