On emerald it says look at the tv and say blue to get latios. I tried this but mom didn't ask you what color the Pokemon was?

After you beat the elite four she will ask you.-but she never did and i already caught the legendaries

http://www.psypokes.com/ has a guide for the brail in Pokemon it also tells you what the brail says so you don't have to figure it out if you can't be bothered.

If you say red, Latias appears and vice versa if you say blue, Latios appears. So it depends on which one you want to catch.

Depending on the location of the braille, it could tell you a variety of infomation, such as how to unlock certain legendary Pokémon.

Gorm.