Both using 6 little “donuts” or one big “donut” would allow you to create animations.
You will almost certainly need to adapt your code to the way you wire it.
I can imagine an object oriented approach where you create an LedTriangle class which contains an array of integers representing the indexes of the leds that make up that triangle.
Perhapse this object has a method that takes in brightness and hue and sets all leds to that value. For more complex patterns, LedTriangle can take a mapping, or even a lambda function, which it interpolates onto the number of leds that make up the shape.
Maybe there is an array of these triangle objects composed within an object called tree. Tree might itself take a mapping, or you may prefer it have some kind of internal logic for proceedural animation.
I actually have no idea what your experience with code is, or what language you prefer, but i hope this gives you some ideas or, at least, some search terms to learn more. 
