Why is color dynamics locked on Photoshop?

[¡Jessica!]

I'm using Photoshop CS2. I'm trying to use the brush tool but no color come sout. So I go to Brush Options and "Color Dynamics" is locked. I try unlocking it by clicking on the lock picture but nothing happens cause the area seems to be grayed out. Why? How do I fix this? Thanks
It is the full version.

Anyway, here's a screenshot: http://img259.imageshack.us/img259/6761/colordynamicslockednt4.png

[drpeppi02]

You have to buy the full version

[America]

Was it free? If so, purchase it.