What could be causing this issue?

Hey if anyone is following this or looks at this in the future, the problem was resolved. Diode Dynamics customer support team was fantastic. Sent me two new lights, and I started by replacing the driver side light (the green-ish one) and they now match perfectly. Crazy how this happened... I was searching everywhere and it seems like no one has ever had this problem. But fear not, DD will take care of you!

 

They are definitely different, I don't think the grass was causing the problem either. Either way, fixed now.

 

I showed one of the pics (not the green one) to my designer buddy and he said the lights were slightly different in color. My eyes still can't see any significant difference. Hah!

 

Not gonna sit here and tell you that pic wasn't included for dramatic affect, but ya, ever so slightly different when looking straight on and it would have drove me nuts in the long run!

 

Out of curiosity, how often do you look at your fog lights? Are't you usually driving when they are on?

Personally, I never turn mine on because we rarely have fog that thick and, even when we do, I don't find the fog lights very useful.

 

Not very often, I only noticed because I had literally just installed them and went out to my driveway to adjust the beams. Was standing in front and that is when I noticed. The pics in this thread are from the night I took delivery & installed the lights.

 

Ha. I sort of like the green.

 

They're good folks, thanks for the follow up!

 

Glad they made it right.

 

OP check all of the grounds associated with this circuit. I'll bet you have a loose or corroded ground.