I would change it (just drain and refill). 

Do a drain and fill. Fluid is cheap and transmissions are expensive. Toyota transmissions don't shead clutch debris like the American transmissions so you don't have to worry about it slipping afterwards.

Scotty answered at 6:27

https://www.youtube.com/watch?v=F9hkDC7oSDc

I meant to add the fluid color is reddish brown and smells fine. The car shifts fine.  Am I asking for trouble if we change fluid and filter? We don't know when the fluid was last changed since the car was gifted to my grandson.

Doing a drain+fill on a car with higher miles is fine with Japanese cars (according to Scotty). Don't flush the transmission it could cause damage at higher miles.