Memory DC

I have two questions

I'm creating a game that utilizes memory DC's (Lots of them!) and I was wondering if anyone knew a way to lessen the size of the individual dc's I'm currently using up quite a bit of memory because of them.

I've noticed that creating one with a smaller picture takes up less space but creating one with a small file size (such as a black and white bitmap format), seems to take up exactly the same amount of space as color ones of the same size. Running windows in 16 bit color also seems to automatically cut the memory requirements in half as opposed to running in 32 bit color.

Since 24 bit color is exactly the same as 32 bit color in terms of quality, can I run windows in that mode to save memory even if its not listed in the control panel? If I automatically change it with a vb program for example will I risk screwing up the computer at all?

I'm not sure if you can! My card (GeForce2 MX 400) doesn't support 24-bit colour, and it bombs if I try to open DirectDraw/3D with it.

A memory DC uses the same color depth of your screen, unless you force it to some lower format.