Q: Pink anti-freeze added to orange Dex/Cool creating brown jelly balls in radiator. 1996 Buick

Hello - the initial problem is that Dex-Cool, your original coolant type, does not hold up well over extended periods, and must be changed every 2 years minimum to avoid the "jello syndrome" you are experiencing. Dex-Cool was first used in some ’96 Buick Models, and didn’t really work out all that well. I recommend a thorough coolant system flush by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, flush your cooling system, and refill with an appropriate coolant type. Replacing your coolant with another low-phosphate, extended coolant such as Zerex G-05 may be more appropriate. Make sure the mechanic knows of your experience with Dex-Cool.