Lets answer this one item at a time.
1) Color Code is just a fancy name for what would be “CTCSS” or “PL” in the analog radio world.
2) Time slots are what makes DMR unique. Your transmit signal is broken into 30mS digital packets and the transmitter switches on and off rapidly. Doing this allows two signals to share the same channel at the same time. One on Time Slot 1 and one on Time Slot 2.
3) Talk groups are the group calls so those listening to that group number can hear you. People have to have that group programmed in their radio and listening on THAT group and THAT assigned Time Slot.