Help with a code snippet

Heia, can someone help with programming something for me, please? I require some code that paints an area a colour. Let's say there's a map of Europe, if you click one of the countries, it fills up the area with a colour. So, if I were to pick Poland for example, it'd slide a colour from left to right until the country (excluding the border) is said colour. I am hoping that the code will say what colour to fill up & and colour to avoid filling up (so it stops at a colour and only fill within the border). for example

IF COLOUR==000 THEN AVOID
IF COLOUR==255255255 THEN FILL

Sorry if the concept explanation is poor. Thank you!

GPAINT does this, I think. I don't have my 3ds atm, but I know it has a border color argument.

I think separating every color section (rgb) with commas will help, because if you say 255255255, the program will think that's one whole number, but 255,255,255 is a group of numbers, separate. You'll also need to put those three numbers in an rgb command so it knows you're talking about a color. color=rgb(255,255,255)