Did some more digging and found these websites with some further clues.
https://www.remotecentral.com/cgi-bin/mboard/rc-discrete/thread.cgi?7718
https://www.avsforum.com/threads/charter-remote-model-urc1060-efc-codes.3053468/
http://www.hifi-remote.com/jp1/lookup/
What I've done so far to reprogram my Spectrum (silver) remote for my TCL Roku TV:
1. Turn TV on
2. Press TV button
3. Press and hold down Setup button until it blinks 2x
4. Type in code 11780. It should blink 2x
5. Press TV button
6. Press and hold down Setup button until it blinks 2x
7. Type in 994. It should blink 2x
8. Press Setup button just once briefly (do not hold down).
9. Type in code 00245
10. Press OK/Select button
After doing all of that it has restored remote control of the tv power, volume, up/down arrows, and OK/select button function, but the right arrow is now also acting like the OK button which is annoying. So I can't navigate the TV Menu to select any apps that are in the right two columns.
If anyone finds out if there is a different primary or secondary code should be using please tell me. Thanks in advance.