What do the different colored icons mean?

A blue and yellow ProZ.com Native Speaker icon () is used to represent native languages that are reasonably certain to be accurate. This includes native languages that have been confirmed by ProZ.com, and native languages reported by ProZ.com members who have sworn that they only have one native language (a native language cannot be changed once it is declared).

A black and gray ProZ.com Native Speaker icon () is used to represent native languages that have been reported, but not confirmed. This includes native languages reported by non-members, even when they only report a single native language.