Do you have one of those pebble-type finishes? It has many issues and horrible reviews. The discolorations can become chips and cracks. Get several opinions from experts, most especially, a representative of the manufacturer of the plaster used. If you have reason to suspect that the plaster wasn't mixed correctly, the experts will be able to tell you.

No it isn't pepple its a dye pack its tahoe blue plaster

The pool ring is typically a tell-tale sign of filling water being stopped prematurely. It typically resembles a ring stain inside a toilet bowl. This may not be the cause for your pool, but the majority of the time it is. When filling the pool it is critical to continuously fill until the water has reached halfway up the waterline tile.