go to the file with the color and make a new RGBA such as
depression, kill, me, now
and do something like this
depression = 1 at the start and than make a loop that goes depression = depression + 1;
and stuff like that and at the end when it hits 255 do this
if depression = 255
{
depression = 1
}
and do that for all colors and it should rainbow or do some random colors i dont really fucking care how you do it to be honest im just giving you an example in C# because im fucking autistic and dont do C++
anyway you get the fuckin idea xd
EDIT| if you follow this exactly with + 1 your going to have issues :|