these are amazing!! I got these for my son and he absolutely loves them!! They do in fact have a rainbow design when they dissolve and also they have a white foam that makes it look like a cloud with a rainbow coming out! These are truly amazing and well worth every penny!! They last a long time as well. The do not dissolve fast and gone within five minutes. We've only used two so far and the second one we used lasted his whole bath! We were getting him out of the tub and it was still dissolving as we pulled the plug!! They do not stain the tub either and leave my sons skin soft and hydrated!! Definitely will be getting more of these. The smell is amazing too there is nothing bad I can say about these bath bombs!!