Conditional Formatting for Unique IDs in Columns

Hi,

I have 2 columns with one column (column 1) having a series of unique IDs. The other column will have the same IDs, plus additional IDs & may be repeated several times.


I'm seeking a conditional format function for column 2 that will highlight matching IDs found in column 1 or my primary set of IDs.

If possible, it would also be nice to have some type of automation that will give a unique or specified color for each unique ID matched.

How can this be done?

Thanks