Help with Distributing Colors and Blending

[AlstonA]

I am having a problem mainly with blending and distributing colors on my canvas when I am painting. The reason why I am failing every-time I try to paint something is that I don't exactly know how to blend my colors together. When I am usually drawing, I continuously use the eyedropper tool to pick up my colors and a brush that has blend set to the pressure of my pen on my tablet. This causes for a "Muddy" look on my character which throws me off from the painting. I wanted to know if there is a tip or solution to solve this problem when I am painting so that I won't give-up on a painting while I am and hour or so in. No, I am not asking for a "Perfect" brush setting, I am asking for advice on the blending of my colors when I am using a Digital WaterColor Brush.

Here are my specs for drawing:
Paint Tool Sai
Corel Painter 12
Wacom Intuos4 (Small) Tablet
Usually paint on A4 sizing with 300Dpi


Here is a set of failed photo's I have drawn in which I have given up due to the blending. This also leads to a odd distribution of my colors while I am drawing as well (Which give my paintings the "Muddy" look).


Drawings

[Kashmir]

Pick colours directly from the color wheel, but be away from the grayish one, try to keep your colours saturated. I hope is that what you are looking for.