Can I top off coolant with another brand as long as it's pink ?

Personally, no, I only use Toyota coolant in my Toyota's. (Same for transmission fluid.) Your local dealership will have them in stock. But, if you don't want to go there, ensure it says it's compatible with Toyota's.
It's, also, not normal to have to "top off" coolant reservoir unless the car was recently serviced and bleeding out air from the lines/engine. You may want to inspect to see if there are any new leaks...it will be pink in color.

 

Aren't you supposed to get Toyota coolant for Jerry Mildred so he can service your Prius.

 

Buy a $1 gallon of distilled water and top off with that unless you buy a gallon of the Toyota premix.

 

Why do you need to "top it off"?
Is there a leak? Or a possible head gasket failure?
How much are you talking about? Is it just below the full line, or way below it?
If it's just below the line, you can add distilled water. Then check it every day or two.
If it doesn't go down, you're okay. But could be due for a coolant change.
When was it changed last? How many miles..

 

Toyota formula has Phosphate cavitation enhancer so make sure whatever pink you use has that…

 

Won't be an issue temporarily, only long term... And because your loss of coolant is highly likely due to a chronic problem with early headgasket failure in Gen3 Prius you'll be draining all the fluid soon anyways, to have the headgasket done. Sometimes you can get a year or more out of a failing headgasket if you only take short trips and avoid hot weather.

 

The Toyota dealer is two miles from my house. If we need more than what you're bringing, it won't take long to get it.