We all know the first rule of attending a wedding is that you don't wear a white dress, so help you god.
The second rule is that you don't wear a white pantsuit. The third rule is that you don't wear anything in a light pastel shade that could be construed as white through a telescope from 500 miles away.
Basically, don't even wear anything approaching the white family, or else the bride has license to throw you out of her Special Day and/or accuse you of trying to upstage her for the rest of your lives.
If you do find yourself in a pinch with nothing to wear but a light-yellow jumpsuit, you should probably go back to square one and buy something else, no matter how fugly.
But another option is to text the bride and ask her if it's okay. One woman learned the hard way that some brides will either lie to you about the appropriateness of said jumpsuit, or forget they ever approved it.