Hello,
I tried your code in a blank workbook and nothing happened. I think I am
doing something wrong as I am not very seasoned in VBA or using it in Excel.

In essence, here is the layout of what I am trying to do (assuming it is
possible).

WorkSheet 1: Summary Page I created (done).
Worksheet 2: Inventory Type 1 that has 100 items (but may up a lot more)
Worksheet 3: Inventory Type 2 that has 100 items (but may up a lot more)
Worksheet 4: Inventory Type 3 that has 100 items (but may up a lot more)
Worksheet 5: Inventory Type 4 that has 100 items (but may up a lot more)
Worksheet 6: Inventory Type 5 that has 100 items (but may up a lot more)
Worksheet 7: Inventory Type 6 that has 100 items (but may up a lot more)
Worksheet 8: Inventory Type 7 that has 100 items (but may up a lot more)
Worksheet 9: This is the SelectedCart that will have the copied items that I
will check from worksheet2 - worksheet8.

The worksheets that have the inventory have various columns listed in B1:D1,
and go on from there, B2:D2, B3:D3, et cetera.

I would like the checked items in SelectedCart to have rotating colors (that
I will select). Is this possible to do in Excel?

Also, if I need to add or delete a worksheet, what part of the code do I
need to amend?

Thank you.