Color Bias – Warm/Cool
I learned that every color has a particular bias (warm/cool) and therefore leans one direction around the color wheel or another. A blue will either be a blue which leans toward violet, such as Ultramarine Blue, or it will lean toward green, such as Cerulean. The same is true with red. A Cad Red Light looks more orange than a Permanent Alizarine Crimson which looks more like a blue red. That’s because Cad Red Light leans toward yellow, and Permanent Alizarine Crimson leans toward blue. The same is true for Lemon Yellow which leans toward green, and Cad Yellow Light which leans toward orange.
That’s how I learned to mix bright secondaries: Purple=Ultramarine Blue + Alizarine Crimson; Orange=Cad Yellow + Cad Red; Green= Lemon Yellow + Cerulean Blue