What colors can you not wear to a wedding?

I have a cute dress that I wore to a bar mitzvah. It has straps and kind of looks like a prom dress but doesn't have any sleeves. From the top to the waist its all black. from there to the bottom (little above the knees) it is black with big white polka dots. Am I allowed to wear this because I heard you can't wear white or black to a wedding?