What to wear to a wedding as a guest? Are these appropiate?

I know there are some rules. Obviously nothing white. Nothing too sexy, nothing too extreme in colours. But I've also read nothing red or black. Pastel colours can look white if they're light enough... Normally I wear black but I tried to steer away from that. I personally love the first dress with the purple flowers the most. Is that dress too much or is it fine? Or too light?