I bought salmon a week ago and wanted to make it for dinner today. When I took it out of the refrigerator, it had a yellow stain on it. What is it?

2. It Could Be Bacteria or Spoilage (When the Fish is Unsafe)

A yellow stain can also be a sign of spoilage, especially if it’s accompanied by other warning signs.

Look for these red flags:

Strong sour or ammonia-like smell

Slimy or sticky texture