Scenario: I have a Hue color light attached to a hub that may or may not be in a group that is attached to a master hub that is connected to my echo. I cant seem to get color controls to work in echo sending things from the master to the slave hub. My setup is that I have an upstairs and downstairs hubs that control all my devices then those hubs are linked to the master hub where all the rules and apps are. This splits up the processing across three hubs but in the case of this RGB light it is giving me grief.
Could you provide more information? First, what are you using to "link" the hubs? There are at least two ways to do this. Second, you say it doesn't work with Alexa. But does it work if you control the device Alexa is trying to control on the "master" hub? That would eliminate the Alexa portion as a problem. If you still think it's Alexa, is it just color control or anything else? What driver are you using on both hubs then?
Is your hue and Alexa both linked to your "master" hub?
My Alexa integration app is on the master hub and my rgb hue light is attached to the slave hub. I am not using the hue bridge integration I am just using the generic Zigbee drivers for all my hue lights. I am not having issues with controlling switch or level status just the color.
I am using hub link not hub connect (tried hub connect but had issues, hub link seemed simpler). I can control the switch and level just not the color via Alexa. On the slave hub I am using the Generic Zigbee RGBW Light driver then I am linking it as a Linked RGBW Light which is what shows up on the master hub an is what is being presented to Alexa via Alexa app.
So, you have your hue bulbs paired directly to HE? Do you have anything else besides bulbs paired to the zigbee radio on that hub?
On that slave hub I have quite a few hue lights ( overhead cans, white bulbs, color bulbs and a strip light) a few SmartThings latest gen motion, Moisture and contact sensors and a Hampton bay fan controller. Again the only issue I ave with any of them is controlling the color on the hue color bulbs. As a work around I have attached the hue color bulb that I need to control directly to my master hub rather than through the slave hub so that I am able to control the color from Alexa. This does work but I would like to have it work through the hub link if possible.
You are going to get terrible performance from all the other zigbee devices on that hub. Hue bulbs are terrible repeaters for ZHA messages because they are ZLL. The problem is, they try to do more than they can. Do yourself a favor, get a Hue Bridge and use the native integration.
Also, I don't know that the hub link supports the commands to go from one hub to the other. It is a little old and was meant to link ST and HE hubs. So, i'm pretty sure it doesn't support the color capability. But hub connect does.
Yes hue bulbs are paired directly to Hubitat no hue bridge in my setup. Also forgot to say that I can control color on the slave hub via Hubitat ui but not on the master hub via Hubitat ui or via Alexa. That being said I don’t think it is Alexa it seems more like a link problem
Not having any performance issues. Forgot to say that I have a bunch of SmartThings plugs as well which act as my repeaters. Response times on my hue lights seemed much faster direct rather than through hue bridge. I did try hub connect before landing on hub link but I had a hard time keeping the hubs in a connected state.
If the hue bulbs were added after all the other devices you will be fine....until you have your first power outage and the hub goes offline. With all those bulbs attached to the hub and trying to act as repeaters when your hub comes back all your routing will end up getting changed and all those messages through your bulbs are going to get lost. There's a reason everyone says not to do what you are doing. But you'll see eventually. Just don't come running to the forum complaining when it happens to you. 
Strange that hub link would have options to link RGB and RGBW lights but not pass the commands for color?
Like I said I am not complaining about performance or any of the issues you mentioned so far I have been very happy with my setup. I am wondering about the color commands sending through the link. If sending the color commands is not doable I have a workaround.
I understand what you are asking.
But above and beyond that, I am telling you, you will eventually have problems. Listen, don't listen...that's up to you.
Those devices also have the switch capability which link does support.
You say you saw hub connect but chose to use link. Why is that? The reason it is simpler is because it doesn't support as much. Did you think you were going to get the same performance from an app that was smaller and simpler to set up?
Do you have any suggestions on the color issue sending through the link?
No....use Hub Connect like you're supposed to.
Thanks for your help Ryan
Maybe someone else will have a different answer but there was a reason that hub connect was developed.
If anyone else has an idea other than “using hub connect like I am supposed to” I would love to hear from you. If connect is my only option I may buy a couple of new hubs and play around with hub connect again to see if I can keep a stable connection between hubs. Would love to get what I have working though if at all possible.
To be clear, does this happen if you manually manipulate the device on the hub it's "linked" to, or is lack of color control only a problem when using an Echo device with voice control as in the original post?
It looks like Hub Link/Link to Hub should support this if there is indeed is a "Hub Link" device exposed with that capability. Support may be interested in hearing more about this. Staff have recommended HubConnect before, so if you're able to set that up, you'll likely get better results (and have more versatility to do more in the long run), but I wouldn't be abrasive enough to say that's what you're "supposed to do"...
