Orange-crowned Warbler

 

 

Usually, they look like this.  Slightly gray above.  Slightly yellow below.  Nondescript.

 

If they get really excited though, they can display an orange crown.  Or if they just get really wet.

 

 

This bird can be found almost anywhere in the U.S. at one time or another.  Mostly Alaska and Canada in the summer.  Southern states and Mexico in the winter.