Since there is an OEM version of this I googled the part number (84231123) and googled "84231123 instructions" which led to this first page:
https://www.coloradofans.com/threads/gm-footwell-lighting-kit-anyone-install-this.432624/
Which also linked to the install instructions for the OEM lighting:
https://www.dropbox.com/scl/fi/uaq2jy24viswplqo58b30/84231123.pdf?rlkey=uwy0094pvwmdctghjo1n8z5yz&e=1&dl=0
Which led me to google "Lighting control module 2021 colorado" which led to this:
https://www.coloradofans.com/threads/courtesy-lamp-switch-signal-k9-body-control-module-x7-for-2022-colorado-cc.441295/
Which led to this:
https://www.coloradofans.com/media/in-this-wire.72889/
You can also view the wiring diagram here:
https://www.gmupfitter.com/wp-content/uploads/2021/10/22_Canyon_Colorado_Electrical_Body_Builder_SM_en_US_2021OCT15.pdf
So circuit 157 is what you want to tap into. This is all over my head though so you may wish to wait on someone smarter than me to chime in.