Hey Connor, Learning color is a pretty daunting thing, I suggest you look at anything that talks about color theory. In a nut shell, there are 3 properties of color to always be aware of when dealing with what you choose: hue, value, and chroma. In your painting, you lack a clear distinction between shadow, light and highlights. This causes your forms to look flat. All your mid tones are the same value, again making the forms feel flat. There are also drawing issues, so I did a sketch to show you what I'm talking about, hope it helps :)

Hi I like how you're focusing on the planes and the light direction in those:)Only maybe try to define the shapes a little more precisely? They seem a little patchy maybe. If it's colour that you're trying to practice I would perhaps focus on simpler shapes. Faces are already so complex and demanding on their own. Maybe some still life or something.