It’s the golden rule: avoid wearing white (unless the invitation specifically says otherwise). Let the bride have her moment. Ivory, cream, and very pale blush tones can also tread into risky territory, so use your judgement.
Other colours to be cautious of? Loud reds can sometimes feel a bit too attention-grabbing, and anything too neon might clash with the elegant atmosphere.
That said, don’t be afraid of bold colour, emerald green, cobalt blue, deep plum, and mustard yellow are all wedding-appropriate and absolutely gorgeous.