I’m still confused on the use case and structure.
If you have a table of Cars and a table of Colors you must already have a table that shows a record with the vehicle make, model, color, age, engine size, transmission etc
If the user is selecting a Car from one table and a Color from another table this is still only filtering the results in the same table so you can show those vehicles that match criteria.
If you want to connect it may be easier to see if I can assist
I’m UK London BST, presume you are USA - EST is 5 hours behind currently.
Happy to connect on Zoom for 30 mins to see if we can get a solution.
May just be me, but the penny is not dropping regarding the structure