Hello, and welcome!
Technically, this is exactly two lines of code (lines 34 & 35), but this may be one of the rare times where I suggest using one piston to pause/resume another. (IMO, it is too ‘spammy’ to leave running 24/7)
Piston #1 (the master) simply resumes/pauses the ‘spammer’ at the correct times, and makes sure the light shuts off at the end.
Piston #2 (the spammer… er, timer) changes the color 3 times every 2 minutes.
Note: Both pistons are required for this logic to work. I recommend naming them similarly.
IE: “SomeName - Master” and “SomeName - Timer”
Pro Tip:
I used colors found in this webCoRE list:
… but RGB hex should work as well. (just add # to the beginning of the 6 characters)