This phrase often describes a deliberate attempt to go unnoticed visually by matching the surroundings. The soldiers had to blend into the jungle terrain to avoid detection.
Pro Tip 2/3
Not Just Literal
Sometimes used metaphorically to suggest avoiding attention or not standing out in a social setting. At the party, I tried to blend into the walls and avoid small talk.
Pro Tip 3/3
Avoiding Distraction
Often used in contexts where someone doesn't want to distract or draw focus away from something else. During the play, the stagehands wore black to blend into the background.