To bleach something too much, usually causing damage or discoloration.
Overbleaching can make things look bad or unhealthy.
Examples:
She overbleached her hair and it turned white.
Overbleaching your clothes can make them fall apart.
The sun overbleached the curtains.
He overbleached his teeth and now they look funny.
The cleaner overbleached the sink and now it's all white.
I overbleached the paper and now it's all crumbly.