That's the power shuttle oil level.
Checked with the engine idling.
If it's red, it's Dexron. Many people use it. It's not the best for a long life.
If it's yellow, it should be a 10W transmission oil - a far better choice.
- don't mix the Dexron & the SAE10W
(Case specify their TCH or Hy-Trans Ultra.)
I just remembered, you have a 580K
Like
@mitch504 said - the rear axle requires a special oil which includes wet brake additive - which you can only buy from CNH