[118]: The image failed validation.

I'm trying to make a team on Team Builders with my own logos, and I'm trying to upload this one image, and it's just a brown sword with light brown highlights, but the website keeps giving me this message: "[118]: The image failed validation." But if I change the color from brown, it works perfectly fine. So I concluded that it just could be the color, but then I realized the other logos were the same colors and they were able to be uploaded with no problem, so it's obviously a bug, so I'm looking for a fix right away