I was going through some files on my old computer when I came across this page I put together with uncolored flags of the Spanish-speaking world. All 20 of them are there and I put eight of them to a page, so they fit on three sheets of paper. If you look closely, the name of the country is written in light grey text on the lower-right corner of each flag. Click here or on the image below to download the file.
So what can you do with them? I can think of a lot of things but one of the easiest and most obvious activity would be for students to research the colors of the flags themselves online (or in their textbooks) and color them correctly. Then they could put them on a large map in your classroom.
But then I got to thinking of a game that would be fun. Review colors and shapes vocabulary with the students before you begin. Then, have students work in pairs back-to-back so that they can't see what their partner is doing. Give one student the blank flags and a box of colored pencils. Give the other student a textbook or a webpage (Hooray for iPads in my class!) with the colors of the flags shown. The students need to communicate - in Spanish - to get the flags colored in as best they can. When they are finished, they should check their work. They will probably have a good laugh too, and learning is best when it is fun.
I hope you get some good use from this, amigos.