This most likely isn't your fault! It's the fault of the people who wrote the standard for video card color depths!

To expand on that, you might exclaim "Ack! I have a leftover bit!" upon discovering that 15-bit graphics and 16-bit graphics aren't very good color depths at all. That is, since a color pixel's value is represented with 3 different channels (red, green, blue), there is always a leftover bit.

In 15-bit mode, the high bit is ignored. In 16-bit mode, it's given to green.

This is also something you might exclaim upon finding out that you cooked too much food. In that case, you should put it in the fridge and do something clever with it later. I've found that leftover bits often go well with top ramen, especially if the leftover bit is some sort of meat product.

Note: There are exceptions to the advice above. If you have leftover ramen, do NOT ever put it in a thermos. The noodles will continue to absorb water until there's none left, creating a foul jello mold that, come lunch time, will slide provocatively out of the thermos with a terrible sucking noise.