I really appreciate your response.
However, the example that I am referring to using this led strip. Which is three separate RGB LEDs, I assume wired in parallel. My other assumption is that, because the blog example is using 7 of these for the digit display, that each one of them is connected to its own RGB channel.
I guess that the only limits would be the 500mA limit on each source channel, and brightness due to the sum of the forward voltages. Which, if I’m understanding the implementation correctly, would be 500mA/20mA = 25 individual LEDs, or about 8 RGBs. Not accounting for the what kind of brightness you would get, which wouldn’t be much, if any, at 9v.
For anyone else that may stumble across this post asking the same question, I read in another post, from one of the Seeed guys that for high power LED, he would recommend not using the onboard source channels for those high current devices, you will let the smoke out, post haste.
So basically, if you want to use several LEDs in parallel or a high power LED, on a single channel of an RD, get yourself a separate power supply with suitable current rating, and high enough voltage rating for the number of LEDs (in the case of a strip), tie the ground to the common ground on the RD and use the positive from the separate power supply for the anode of the current hog(s) instead of the onboard source driver.