Hello, XXXXXXXXX
Linoeic acid is omega 6 fatty acid which is good for her and her coat. It can not change or alter color of hair. It does a great job strengthen hair and softening it, which is why it is in a shed relief supplement.
Weather can alter hair. In the summer hair loss is inevitable. The top coat thins exposing the under coat more. The under coat can be a different color than the top coat. If she outside a lot sun can alter hair color too.
Also as cats age, hair color changes are common, and not just getting white or gray hair like us with old age, but lighter, darker, etc. I have a diluted blue calico and as she has gotten older her blond patches have almost all turned to a creXXX XXXXX.
I wouldn't worry about a bit.
Sincerely, XXXXX
Expert in cat behavior and health
Expert in cat medical and behavior issues.