If I am using .Net and SQL Server 2008, what is the best way for me to store a color in the database, should I use ToString or convert it to an integer, or something else?>
Depends so much on the type of color you want to store. Eg. if it is from a fixed palette then a short int or even an unsigned byte might be sufficient.
3 byte RGB or 4 byte ARGB (A=alpha, ie. transparency) could fit into 32 bit, so a 32 bit unsigned integer type would work. This is the standard for most applications. However, you might want more - in which case a 64 bit unsigned integer might be required.
Alternatively, if you want to modify or query the color according to its components, I would store each component as its own unsigned int (ie. Red, Green, Blue, Alpha fields).