World: r3wp

My first though is to have a map (an image) of countries where each 
country has its own color (call it a color-map) and another map of 
the same size that you display (diplay-map).
Then you have a block of pairs [country-name country-color].
So like this you have a relationship in any sense.


Click the displayed map => find the corresponding pixel in the color-map 
=> find the country name in the block.

To know the edge of the country you want to fill, just find all the 
pixels of this same color in the color-map and poke the corresponding 
pixel on the diplay-map.

jave=have

yes, a precolorized map would make things simpler. thx didec...