Photoshop :: Coloring In Layer Group

I am using Windows 7, I have Photoshop CS5.5 and am improving a bit in my digital illustration/coloring. I was experimenting with organization by using layer groups. When I did this and began to work on the colors, I noticed them behaving very poorly. For one thing, they always came out brighter than I intended. No matter how I tried to darken the colors, they always either fixed to a certain tint or just got brighter when I tried to darken them.

I noticed them interacting with the colors on all of the other layers, even with layers outside of the group. So to get around that I tried erasing wherever colors overlapped. This did not work, it only removed the mixing of colors, I still have really bright colors on everything I paint. I did notice though that when outside of a layer group, all of the colors behaved normally! Yes I know I can just keep the colors out of the group folder to fix the problem, Why do the colors misbehave within layer groups? Why do they respond with a transparent nature(for lack of a better term)? And is there a way around that?
 
I did check the opacity of everything and everything was at 100%. I did check the blending mode of the group and the individual layers, I had them all set to normal.