You may have seen or even captured an alternate-colored Pokemon. These extremely rare colorations are called shiny Pokemon. Shiny Pokemon sparkle when they are released from a Pokeball or encountered in the wild.
SHININESS MYTHS
Shiny Pokemon are stronger/weaker than normal Pokemon!
Although some shinies may appear to have different stats, the myth that shinies are stronger or weaker than normal Pokemon is false. Pokemons' stats are determined by Personality Values, and these are randomly generated when you encounter a wild Pokemon. (There is one exception to this. In GSC, shininess was determined by a Pokemon's IVs, making them generally stronger than normal Pokemon. This has since changed, and shininess is no longer based on IVs in recent generations.)
There is a shiny [insert name of Pokemon] on Route [insert route number]!!!!
This is partially false. Shiny encounters are completely random, which means you could find a shiny when you least expect it (I once ran into a random patch of grass and the first Pokemon I encountered was a shiny Starly. This happened once again on a different route while I was looking for wild Chansey). There is no sure way to tell if you'll encounter a shiny or not unless you're using the PokeRadar to hunt for them. Remember, shiny PokeRadar patches sparkle. I'm sure you'll recognize one right away. If you see a sparkling patch, put on a Repel and go get your shiny!
If you do _______, you will find a shiny Pokemon!!
This is false. There is no sure way of encountering a shiny Pokemon. It is random, and there is approximately a 1 in 8192 chance of a single Pokemon encounter being shiny. (The ONLY guaranteed shinies are the red Gyarados in G/S/C and the Zigzagoon from a previous Pokemon event.)
If you evolve your Pokemon, it will no longer be shiny!
This is false. A legitimate (not hacked) shiny Pokemon will stay shiny after it's evolved. However, it can sometimes be hard to tell the difference between a normal and a shiny. Garchomp, for example, is just a hint lighter than its normal coloration. An easy way to tell if it's shiny is that a shiny Pokemon will have a red star in its profile.
If you have any more rumors you need busted, PM me and I'll answer your question!