Monday's Riddle! I Am, Therefore, I Am...

This riddle practically wrote itself : ) It's going to be an inspirational week! Thanks to children's author Gueh Yanting, Claudine- you have inspired me! ~ F

I am the light in the window of you. I am the bright in all that you do. Whatever it is that is timeless and told, whatever is green or whatever old. For, I am the one that completes the circle, whether it be pink, cerulean, magenta, or purple. The colors are there to use. The design is yours to choose. I am the magic spark that turns the page, the invisible entity that sets the stage.


What am I? 

Here's a clue!