The first effect_handle value is reserved for level tinting. You can free this default effect with
FreeColorEffect() or ModifyColorEffect().
Once the default effect has been freed, it's number can be used for a new effect - this allows you to have 31
custom effects.
White Effects
An RGB tint of '1 1 1' is white. If you added this with
AddDynamicTint(), you would see a yellowish tint. But, add this tint with
group 1 or 2 of NewColorEffect() and you will not notice
any change (this does not apply to effects which add to the screen).
Cumulative Effects
Color effects are cumulative. That is, color effects are combined when more than one effect is used
at the same time. With some graphics cards, using more than one of NewColorEffect()'s
effects will cause problems.
Adding Color to the Screen
The maximum integer amount of color that can be added to the screen (with
AddDynamicAdd() or NewColorEffect())
is around 290. The real limit may be higher, but because 290 is opaque, you're not going to notice anything above that.