Return Hose Changing Color

[kadamik]

I have re-enforced silicone hoses for my return and overflow system.
I have noticed that my return hose has moved from clear to a yellow-brown color. The 3 overflow hoses are perfectly clear. Just wondering why and if I should replace them?

 

[Idoc]

Are you sure it's just not some algae starting to colonize the clearer tubing? If you have a light source near that tubing line, it will definitely start to grow some stuff in there...especially since most of us have our heaters in that return area therefore the water is a little bit warmer.