How do I change the format of a Caption so it is always the same and I don't
have to change it each time?

I want the captions to be; bold label, unbold caption

BoldFigure 1.2:End Bold This is the second figure

My problems are that it is all bold, and that it come in 10 font and left
justified.
I tried creating a style for it, so I can just select the text and change
it, but it make everything bold (or not bold).

Any ideas?