Pick a country and depict something which you associate with that country. That might be a person, a dish, a location, or anything else.

Your palette is the exact colors that you find in the flag of the country in this wikipedia list. No AA colors or inbetween colors, only the main colors of the flag. Colors used in the emblem icons on flags are also allowed to be used, however should there be many colors in a flag then the maximum amount of colors you can use is 8. No extra colors, so for many countries this will become a 2 or 3 color piece.
If you click on the flag name in the list you'll most often find hex color codes in the wiki article about the flag.

The size of your canvas will depend on the flag you pick, it needs to match the same width/heigth aspect ratio as the flag. You can find a list of aspect ratios here. So for example if your flag has an aspect ratio of 2:3 and you make the height 50px, the width becomes 75px. If you don't know how to calulate this: Multiply your height by the number in brackets () on the wiki page. If you choose a flag with an irregular shape your canvas needs to match that shape, and the rest of the canvas is transparent. Maximum height is 80px.

This challenge idea comes from keeling00

Canvas Size - Height: max 80px. Width depends on the height and the flag you choose.
Colors - The main colors of the flag you choose only, as given by the wiki page. Max 8, should there be more colors.
Transparency - Only if the country you choose is Nepal. Otherwise no.
Animation - No.

The challenge thread will have all the challenge updates. The thread is also a great place to post your WIPs.