Create production schedule with drop down menu and color fill of cells below

Hello everyone,

Thank you for taking the time to read this.

I'm struggling to make a simple job production schedule. I'd like to a column list the time in 15 minute increments and in the next column be able to select a part number from a drop down list that automatically fills in the appropriate amount of time. So if I select part #1 it would automatically fill in 8 cells with the color yellow. Directly after the yellow, I could select part #2 and it would fill in the next duration with the color of blue etc.

Eventually there will be a lot of part options so I need to be able to quickly select the part and see the impact.
I've attached a quick workbook with what I'm imagining.

I feel like this should be easy but I am not making any progress.
Thank you for the help.

See if this suits your need. Choose the times required from the parts cells.
While it will only do 1 round of the three parts, it colour codes and adds time as I understand you want it to. Albeit very inelegant.
You can easily add a fourth or fifth part if needed, rinse and repeat.

Stay safe

neilosj