Yellowness on tubing

Has anyone else experienced a light yellow color around the tubing of the resevoir?? At the base by the pump my first time seeing it not sure it is something I need to start looking for or just sometimes I’ll have tubes like that…

I’ve never experienced this before. Do you think it is just on the outside of the tubing?

i think it is, cant tell but uits not affecting my insulin intake i dnt think lol