The Guam flag is very distinctive and will be a fun one to colour in, I think. Just print out our colouring flag and grab your pencils...
Guam Flag Colouring Page
Here's a colouring flag of Oman to print for the kids. The central and left section is a bright red, while the crest stays white and the bottom section is green.
Here is a colouring page of the Bahrain flag, ready to be coloured in with its striking red and white design.