I am running 4 ColorKey LED Par 64 on an Element. How can I control each of the 3 colors?

A channel on Element can refer to a single dimmer, or a fixture with multiple DMX addresses and parameters.

A great place to start is with the ETC Video Library available on Youtube.  Here is a link to the Element Tutorial Series:

https://www.youtube.com/watch?v=BpM-lUtGbyM&list=PLF269237482F9B97A

i think it's important to get the terminology straight: in the shiny world of dmx we have two numbering schemes: one is the dmx addresses that the console uses to the the real world what to do. the other numbeing scheme is the channel number. that's what you use to tell the console which fixture (i.e. metal box that emits light) you mean.
you only work with the addresses once and that is when you assign the addresses to the channel numbering scheme. this assignment is called patch. with dimmers it used to be what we call 1:1 now which is DMX address 1 (i.e. dimmer 1) also is channel 1. but with stuff that needs more than one address like your led pars you might not want to use channels 1, 4, 7, just because those happen to be the addresses. so you can i.e. use channel 2 to make the console talk to the fixture that uses dmx addresses 4 and 5 and 6.

so whenever you control lights in your console you use the channel number. since fixture like your leds can have different properties (like red, green and blue) you need a way to tell the console which property of a certain channel you want to control. as soon as you select a channel (that you previously patched), the console knows which properties it has. it can show them to you, i.e. if you open the Movinglight Controls display by pressing the button ]ML Controls].

i think it's important to get the terminology straight: in the shiny world of dmx we have two numbering schemes: one is the dmx addresses that the console uses to the the real world what to do. the other numbeing scheme is the channel number. that's what you use to tell the console which fixture (i.e. metal box that emits light) you mean.
you only work with the addresses once and that is when you assign the addresses to the channel numbering scheme. this assignment is called patch. with dimmers it used to be what we call 1:1 now which is DMX address 1 (i.e. dimmer 1) also is channel 1. but with stuff that needs more than one address like your led pars you might not want to use channels 1, 4, 7, just because those happen to be the addresses. so you can i.e. use channel 2 to make the console talk to the fixture that uses dmx addresses 4 and 5 and 6.

so whenever you control lights in your console you use the channel number. since fixture like your leds can have different properties (like red, green and blue) you need a way to tell the console which property of a certain channel you want to control. as soon as you select a channel (that you previously patched), the console knows which properties it has. it can show them to you, i.e. if you open the Movinglight Controls display by pressing the button ]ML Controls].

OK so the ML Controls is the easiest way to get to each of my colors I'm guessing. Is there another way? For example, if I bring channel 401 (one of those fixtures) to full, all three colors come up to full. I see that I can get to the separate colors via the ML Control but could I access it as if it were a normal channel? Like 401.1 at full for the red, 401.2 at full for green, etc? Or is all the control through the ML Control options?

You can program 3 subs to be the three colours so you can mix and match as you go. Handy for busking live shows.