Figure 1.--The boys and girls at this Portuguese school wear pink smocks. Note the destincvtive square collar.

Colors currently vary with each school having destinctive colors. I'm not sure what colors were formerly worn when they were common at public schools. Quite a wide variety of colors are worn at the different schools. Many private schools still require smocks and as a result quite a wide range of different colors are worn as school smocks. One HBC contributor reports, "Each school has it's own uniform. At my son's school, both boys and girls wear royal blue smocks."