Help???

Okay, I'm questioning putting this up here buutt I'm really confused x3

How do you color things in on Paint Tool Sai?? I've played with it a lot and I can't seem to figure out how to color. All the pictures I make on it i always have to outline it and color it in Paint... I realize if i've played with it so much how i couldn't know how to color...but i dont Dx

Can you help me??

Iff you can thanks :3