Wall breaker

My hands are beautiful
With them, I work
With them, I build
I build beautiful things
As beautiful as my hands

My only unpleasant building
However, is a wall
Built so high
Even the builder could not climb
A wall I painted black

A distance away from my wall
I wonder how I built it
I want to take it down
I should not
I cannot, even if I tried

All of a sudden
My wall cracks
And the black turns white
How it cracked
That, I do not know

This wall will fall
And so it happened
Crumbling down completely
And behind was my wall breaker
He turned my black to white