Trying to hide alpha channels

[Kabooss]

Hi, so basically I'm trying to make a BattleShips GUI for my computing science project (I've done all the coding for a simple command prompt version)
I've pretty much just started, got my windows form running, and am trying to create a gameboard... my plan was to place a 10x10 grid over the top of a richTextBox then fade the background (placing the ship images into the richTextBox, to make it appear as if ships were on the grid) and the alpha channels on the grid I made work just fine, but when i set the background color to transparent, it just appears as a white background!?

So in short, my question is, How can I (remove?) the background or make it totally transparent so I can see the richTextBox behind it, or could you suggest a more appropriate or easier method for displaying little battleships (all 4x1) on a grid...

Many thanks, Alistair

.. I would add an image to show you what I'm trying to explain but i have no idea how to in C++ forum (if you can?)