Colored PE changes the color of the graphical user interface. Currently blue and purple are the only available colors to choose but in the future more colors will be included like red and green.
It should be noted that only the interface, like the buttons in the menu settings, will be blue or purple. Not the actual block and item textures.
ColoredPE Minecraft PE Download Link:
Purple Color: ColoredPE MCPE 0.11.x – PurplePE v1.0.zip – 832 KB
Blue Color: ColoredPE MCPE 0.11.x – BluePE v1.0.zip – 836 KB