Coolant color

Well, I just took the family to Disney World in Orlando and back here to Fort Worth. We had a great time visiting all of the parks and seeing as much as we could in a week. The kids really loved it. We stayed at Fort Wilderness camp ground, which was a really great place. It was much cheaper to stay there in our pop-up camper, than to stay in a resort hotel!

Before leaving, I had the truck checked out by a local dealership and had the oil/filter and fuel filter changed, along with a complete check to make sure things were fine.

After getting back, I changed the oil and filter again because of the 3000 miles we put going to and from Orlando. While I was changing the oil, I noticed that the coolant in the overflow bottle looked dark. After opening it, I noticed a film on the top of the coolant. I took a coolant test tool and sucked up some of it from the bottle. It appeared to be a cloudy, dingy orange color, instead of the clean color. I had the whole system flushed and refilled back in December by the dealership, so it is relatively new. I am wondering if I should get it flushed and filled again. I did tow over 2,000lbs for 3000 miles or so with overdrive locked out and tow/haul mode on. The temp was perfect the whole trip. Any expert opinions would be appreciated!!

Sincerely,
Matt