rgb channel problem?

Nope, can't say as that I have.    I'll take it that you've got v1.11 firmware on the DCx16 and that you are not using the enhanced effects (ramping shimmer, etc.).  Something seems to be confusing the commands being sent to the board and my best guess is the ID selection.

Place the ID's in sequential order.  Instead of 1, B, C, try A,B,C, or 1,2,3.  If that doesn't work, report back and we'll try something else. 

Start by eliminating the simple things: 

The boards are all running firmware v1.11, correct?
You are not using enhanced effects (e.g. random ramping twinkle), correct?
The boards aren't set to servo mode (from a past show perhaps), correct?
How are you are connecting to the boards?  CAT 5, wiLink, or both?
You only set up your first board as a "D-Light DCx16 (1.13+ firmware)" (ignore the 1.13+, it's a misnomer for the DCx16 which is currently at v1.11), correct?
After that you right clicked starting with the first channel and, choosing channel properties, you ensured that "D-Light RGB over ACx16 or DCx16" was selected, and then you entered the RGB channel information properly for all 16 channels, correct?

Are we good so far?  If so, what commands are working for you and what commands are not?

This probably won't make a difference but something worth trying is to set the entire board as RGB instead of 15 out of 16 channels. 

Forgot to ask, what is the Data Rate (Settings, Serial Network) set at?  56000?

Did you set up your boards so that all the red are on one board, the green on another, and the blue on another, or did you set it up as channel 1 is red, channel 2 is green, channel 3 is blue, 4 is red, 5 is green, 6 is blue, etc. on one board?

Do ramps work for you?  Is it just off commands that are the issue?  Have you set an intensity at 0% and placed it in a cell, or just not programmed an effect in the cell / used the 'X' tool?

There is quite a lot going on behind the scenes right now (please be patient if this isn't resolved immediately), but I'll try to find time to replicate your issue with my two DCx16 boards.

I am not able to replicate your issue here.  All commands on my board are received fine, but to be fair I am using a different version of Aurora than you are.

Since you are using the RGB tool to program effects, try programming a Set Color command using hex value "010000" (or just put a '1' in the 'R' spot and leave th others fields set to '0').  This will send an on command to the controller, albeit one that is such a small  intensity that the lights shouldn't even respond.  Let me know if that works.

If not, try creating the channel from scratch, not by making a controller first and then editing it, but by right clicking and saying 'add new channel', then choosing RGB and assigning the channels to it.

Glad to see you back on track.

If it happens again, you might want to write down the errors you were getting in case Micheal wants to see them once things get a little less crazy.