Hello,
The Color Code is like PL or DCS, to prevent other users from accessing a repeater or interfering. I have one Connect Plus system that sets it to zero at all sites and another that sets it to the site number modulus 16. Most Capacity Plus and Connect Plus systems around me use the same color code for all frequencies at a site, but I would not depend on it. All the radios that use a site are programed with the frequency and color code of each repeater (Channel pair) at the site.
The Capacity Plus system will do a brief burst every couple of seconds on the rest channel. So if you hear it and DSDplus displays rest, then you have the channel pair. Other channels displayed gives you clues of other channels in the system. All the radios that are idle are listening to the rest channel.
What makes things a little complicated is the long, maybe 5 seconds plus, idle bursts. A rest channel is displayed but it is for another frequency. The radios know the frequencies at the site so they will move to the rest channel. I suspect this transmission is for straggler radios. Sometimes activity on other channels will be shown.
The system will allocate the rest channel to the next active talkgroup and move all the idle radios to another channel, the new rest channel. When the transmitting radio is finished, all the radio in the talkgroup will move to the current rest channel. If another radio transmits a response in the talkgroup, the current rest channel will become allocated to the talkgroup and a new rest channel will be allocated, if available.
As I mentioned before, if only one talkgroup is active at a time, the above action results in the talkgroup and the rest channel switching channels on the same frequency (1->2->1->2). This makes it difficult to figure out other channels. As soon as a second talkgroup is active, both channels on a frequency are active so the rest channel has to move to a channel on another frequency if available. It the system becomes moderately busy, the rest channel will tend to rotate up through all the channels.
It takes some work to piece systems together. I started by searching each band and making note of the frequency, color code, channel pair, and signal strength of bursts I heard. I also noted any active capacity plus channels and any channels displayed, but did not pin the channel pair to that frequency. Signal strength can be helpful as frequencies at the same site tend to be of similar signal strengths.
You need to search over time as the system will only send the brief burst only on one frequency at a time. So if you find brief bursts on Channels 1/2 on one frequency and Channels 3/4 on another frequency at the same time, then they are likely different systems. If the rest channel moves off of Channel 1/2 then search and see what frequency with Channels 3/4 becomes active. See if the same talkgroups appear on different channel pairs.
73 Eric