Here's a colouring flag for Laos. The circle in the middle - which should be left white, is said to represent the moon shining on the Mekong river! Colour the central stripe blue to represent the river, and the top and bottom stripes red.
Laos 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.