So I opened the menu_gfx.png file and there are 4 lines, orange, blue, white, and blue. I understand the orange line is the active button, if you offset it vertically -30px you get the blue 'mouse over' color. My question is what are the white and second blue lines for?
Hmm, the "white" is really gray. But as so many others, you apparently have a difficulty seeing the color.
It's used for buttons such as the "Mark all messages as read" on the board index.
Oh good to know. What's the last line for (the second blue line) and is the white below that used for anything?
All (real) white is just transparent area. The second blue is to modify if you like want a 3rd color for hovering effect.
Great, thanks very much!
As an added note, if it helps, whenever you encounter something like that I always found it best to just search the index.css with the px offset, and look for the image file you are working with.