This is also happening when I'm only using the brush tool. The gif is using the brush tool with one color on top of that same color. This pixelated look is common and the color picker recognizes this as multiple colors.

Running Windows 64 bit version
When I use the fill tool next to color I put down with a brush, the color ends up looking different, and if I brush over it, it changes to a blend of the colors.

I just downloaded PSS, and I've encountered 2 major problems. 1: Whenever I draw curvy lines, the system tries to jump the gun and skip the "curvy" part. It cuts from the beginning of the curve until the endpoint, resulting in a line I didn't want. In the picture I included, I held my wrist in place...