pink (kodak/lucky) or light blue (fujifilm) is the color of undeveloped emulsion. The photo paper is starting to break down. Was it a bad wash? Possible but not likely. Bad color developer? Possible but there would be streaking and not so much spotting. It's more like a bad batch of photo paper. Scan from negatives to reprint your photos is the best option.
The other (remote) possibility is degration from reflected sunlight or ultraviolet light, like through crystals or glass at an opaque angle that dispurses the light.
Wow. I will have to try this. Thanks so much!