Availability calendar using conditional formatting

Hi all.

I'm hoping someone can help me out with a formatting issue I’m having please?

I’m trying to create an availability calendar, similar to what you would see if you were booking a restaurant online I guess. It’s so my team can see how many hours are available to take as time off, as they are not permitted to see the main holiday sheet.

I have no problem linking the hours available from one sheet to the other, but I’m struggling with formatting the cells. I’ve tried several ways including conditional formatting, but I can’t seem to get it right.

I’ve attached the sheet so you can see what I’m trying to achieve. Any help would be appreciated

Thanks a lot,

Tony