The brain is divided into two halves (hemispheres).
Usually, the left half of the brain controls the right side of the body.
The right half of the brain controls the left side of the body.
your right brain tries to say the color and your left brain insist to say the word, thus, causes you to slow down the process.
Comments
I'll give you one to think about. On a personal note, I'm left hand dominate. According to popular scientific theory, my color is blue in this illustration...
My best guess says, you more than likely get a bit of ink stains upon your own left while "pushing the pen". Great posting my friend. :)