Value studies...

So an area that I struggle with when painting is value.  I can make black and white paintings and drawings with perfect value but I have a really hard time understanding the value of color.  I mean it's pretty easy to see that a dark blue will be on the darker end of the scale and a pastel would be on the lighter end.  It's the mid tones that get me.  And yellow throws me off a lot I think.  I sometimes use yellow for highlights and it ends of being more of a mid tone and makes the whole painting flat.  Anyway, here are a couple value studies I did last night.  I'm anxious to see if they help my painting at all.  :)  I would love to hear any advice you have as well!

And the finished painting!  I think the value study helped a lot!