diesel engine coolant color differences??

For your Cummins engine, Cummins Coolant Requirements

Coolant does come in many colors, not a reliable way to choose your coolant Coolant color chart

There are several different chemistries of approved coolants for large diesels:

Low siliate for diesel with added SCA (Supplemental Cooling Additive). Sometimes referred to as DCA (Diesel Cooling Addtive). This is the "regular" coolant and SCA/DCA level must be test and replenished (it is used up protecting the cylinder liners of linered engines. Most recommend 3 year replacement in addition to annual SCA/DCA testing and replenishment.

The new generation OAT based coolants. Think of them as "maintenance free" coolant. 6 years, put them in and forget about them. Yes, if you drive more than 300,000 miles during that time, you have to add a one time booster.

While I doubt your coolant will "turn into a pumpkin" if you mix them, you would have to have an advanced degree in chemistry and know the composition of each to predict what would happen if mixing coolants of different chemistries.

But, I guess my question is "Why would you even consider doing it"? Carry an extra gallon of what ever coolant you are using. If a regular coolant, also test annually with the test strips and have either a coolant filter with SCA/DCA or liquid SCA/DCA on hand.

The Ford recommended oil for my diesel was the worse oil ever and I send samples of 5 different oils from my engine to lab.
For diesels that don't need SCA balancing I am using Mercedes coolant. It has something to it as my pickups after changing to it don't run radiator fans very much if ever.
For wet sleeves Detroit I went to commercial people and am using Fleet Pride lifetime coolant.

The last coolant change I used in my cummins was red in color. It was Shell Rotela brand.

Read your owners manual and dont listen to auto parts guys and others. My owners manual has a diesel engine supplement also. My 2014 CTD uses OAT and warns of damage if using HOAT and says never use universal or "world" coolants. I believe that's how they worded it. Depending on the light OAT can appear orange at times yet it's purple.

It says if you have to add HOAT in an emergency situation change it soon.

Search Hoat, oat, poat, nmoat, pg, noat, iat.......

Found this that specifically mentions Cummins engines.

as a auto shop owner I see red coolant green coolant blue coolant every manufacturer will say theres a difference but I use a universal coolant in all of my customers cars and have never had a problem