Highlight Cells based on Cell Reference on another Worksheet

I am trying to find a way to automatically highlight all the cells specified by the cell references in a column on another worksheet (which will constantly have new values added).

On the attached sample, the 'Data Before' tab shows the base data before any highlighting. As cell references are added to the 'References' tab in 'column A' I want the respective cell to be highlighted on the 'Data Before' tab resulting in the 'Data After' tab and each time a new cell reference is added to the 'References' tab, the respective cell is then highlighted on the 'Data Before' tab.

I would like to have control over the highlight colour so that a different highlight colour can be specified for each date change, i.e. all cell references that are shown on the same date are the same colour but where the date changes a different highlight colour can be specified.

I'm really not sure where to start so any help would be welcome.

Many thanks