Can you identify the flag on your right?
If not, you should try Flag Identifier - an online search tool to help you quickly identify flags based on their color, shape (not all flags are rectangular), geography or even the design pattern printed on the flag (vexillogram*).
Coming back to our example, you can search for this particular flag through the tricolor option but limit your search to flags that have orange, white and green colors. You’ll only find two countries that have flags of similar colors - India is one but your answer is the second option - Niger.
Here are some more terms related to flags that you may find interesting. The person who designs a flag is called vexillographer but someone who loves collecting flags is knows as a vexillophile. The study of flags is known as vexillology and the pictures or design printed on a flag is called vexillogram. [via]