When doing color tinting, keep in mind how the blending actually works. (Test things in Photoshop with blending modes). With Multiply, the closer to pure white your base color is, the more or your overlaid color you get. With Overlay it’s the same but with 50% grey.
Use the red channel from the diffuse to multiply other colors on top to maintain existing diffuse areas that should not procedurally change; retains the original diffuse as a main color scheme. Results below:
