It will make life simpler if you change row 7 to the same format as column B. For example, in C7, replace "7-8" with "07:00-08:00".
Then you can use a "common" conditional formatting formula for the bar cells. In C8, the formula would be AND(LEFT($B8,5)>=LEFT(C$7,5),RIGHT($B8,5)<=RIGHT(C$7,5)).
You can copy this formula to all the bar cells. If you want different colors in the rows, you will need to adjust the action on a cell by cell basis.