Colorlocks are long blockers with a number displayed on them. Pets and blasts cannot move through them, and they stay fixed in place on the board until they are removed. Colorlock blockers are resistant to blasts, and won’t be affected by matching adjacent blocks.
To remove a Colorlock, match blocks of the same color anywhere on the board. You’ll notice that the number on the blocker goes down for every block of that color you match. Once the number drops to zero, the Colorlock will disappear.