Slaphappy, the GOAL percentage is different from your final SCORE percentage. From the research and digging myself and my TL have done, we know that actually obtaining prices for between 65%-80% of your items will net you a total comp shop score of Green. (Putting you with the desired minimum score of 87% total score to be green.) It sounds like someone is conveying the percentages to you incorrectly.
Do too little of the shop, you'll be yellow or red.
Do too much of the shop, you'll be yellow or red.
There was confusion back in the day when we first started comp shopping. The guy before me misheard the TL. He attempted to complete 88% of the items with price. RED. So, I can confirm that too many items will affect your score.
I'm almost always green. I obtain prices for between 70-75% of the items on my list, and mark the rest of the items as "not carried" since that is what best practice tells you to do. (Check it out on workbench.) That was my list is 100% "complete" meaning each item is reported as a price, not carried, and occasionally not available.
I would aim for 70% with price, try doing the other 30% without price, for 100% completion and see what happens. If you have 88% with price, you're most likely going to see a red or yellow score for the week. 🙁
If something still seems off I'd have your TL start a mysupport ticket.
I hope you get things figured out!