Color is a bitch. I'm not very good at it but I don't take painting very seriously and my education in such things ended in high school. I have a BFA but I studied graphic design and sculpture.

Just practicing exercises like this would help:

It's an easy to learn, hard to master kind of thing.

You might also like ink wash to give value. You need watercolor paper but it's a bit less technically demanding that learning how to effectively stipple. Get some brushes, india ink and a well pallette, it's basically a hubski logo that holds liquid:

Put about the same amount of water in each well. Leave one clean water, then put a drop of ink in one well, two drops in the next, three drops, until you have a value scale from very light to pure black. Aqueous media isn't easy either, it bleeds and runs if you aren't patient or don't know how to control it, but it's a fairly straightforward means of creating a value scale.

Don't expect to run before you can crawl so making little squares of varying shades of hatching or ink wash isn't fun but it's how you get to the level I think you want to be at.