Ok. Here is what I have to do. It sucks that the IMG tag is off, it seriously should not be cuz it inhibits proper explanation of a problem. Anyways, what its supposed to do, is go through each pixel in the 50x50 pic, and if it's a shading of either magenta, blue, or green, replace it with the appropriate shading of the other color contained in Color(X, (r1-b2-andg3-values)) so here is the code:
Code:
    For i2 = 0 To 49
        For i3 = 0 To 49
            pixel = GetPixel(Picture1.hdc, i2, i3)
            If pixel <> &H8000000F Then
                For i4 = 0 To 15
                    If pixel = RGB(90 + i4 * 11, 0, 90 + i4 * 11) Then SetPixelV Picture1.hdc, i2, i3, RGB(Color(1, 1) * (i4 / 16), Color(1, 2) * (i4 / 16), Color(1, 3) * (i4 / 16))
                    If pixel = RGB(0, 0, 90 + i4 * 11) Then SetPixelV Picture1.hdc, i2, i3, RGB(Color(2, 1) * (i4 / 16), Color(2, 2) * (i4 / 16), Color(2, 3) * (i4 / 16))
                    If pixel = RGB(0, 90 + i4 * 11, 0) Then SetPixelV Picture1.hdc, i2, i3, RGB(Color(3, 1) * (i4 / 16), Color(3, 2) * (i4 / 16), Color(3, 3) * (i4 / 16))
                Next i4
            End If
        Next i3
    Next i2
Ok. The "If pixel <> &H8000000F Then" line is so that if its of the background color, it doesnt have to go through all the other if's. Anyways, the problem is that it's incredibly SLOW!!!!!!!!!!!!!!!!!!!!!!!!!
To demonstrate how slow it is, you can download the latest version of my game thats in the process of being made here:

http://www.geocities.com/vvuueenn/rts.ZIP (70k I think)

The time it loads is the time it takes to change the colors in approximately 100 50x50 sprites, or 250000 pixels. On my comp it takes about 5 or 6 seconds. This may not seem as much, but this is done AT RUNTIME in games like starcraft. Besides, when the game's done, there wont be 100 sprites, there'll be more like 10000 sprites, TIMES the amount of teams (races), and a 20 minute load time before you can start playing before EACH GAME is not exactly cool. SO! I need a faster way to replace pixels. IF ANYONE KNOWS HOW TELL ME!