Error in block textures / Change, they distort.

My problem is when I am playing Minecraft, while spending time playing, normal Minecraft textures are distorted, the color of the blocks changes and their shape ... I can't find any solution anywhere for what happens to me ... Example: the wood changes color, the grass changes shape and occurs in all the blocks ... Although I put a package of textures in the game the same thing happens, I don't know if it's a mistake, but if you have any solution for this, Tell me I'd appreciate it, since I don't want to stop playing this great game.