@ Bad Medicine; Make sure you haven't used any BBcode tags (italic, bold, size) inside the gradient. A gradient doesn't work if you try to use tags within the gradiated text.
@ All You Need Is Ice_ You can find them in the BBcode section of the Help pages. I think a few commonly used ones are Times New Roman, Verdana, Georgia and Courier or Lucida Console.
Sure, it's simple to drag the cursor around but generally speaking, people who make eye-catching signatures & aren't newbies generate color schemes from their avatar so the colors are an exact match. Plus, it takes lesd time than trying to select colors for yourself. ColorPicker is less useful in this sense- really not useful at all for making a nice theme. (I'm speaking from five years of experience)
@ watson2013 You have to go to the Profile section of your My Mibba page, and then find the button that says Signature. That's where you type or paste the signature code.