Colors don’t “add”.
What 1 plus 1?
Is that a valid color range?
Easiest way to change a color is to lerp the new one onto it on a desaturated texture as alpha.
Hardest way would be doing the math to shift the hue of the underlying texture.
You just need to find and follow some better tutorials to learn the basics is all.
Revisit the material after you do so, and things will be a bit clearer/maybe even simple…