Holiday Calendar Problem

I have devised a holiday calendar for employees (see attached). All works fine on the individual employee worksheets using the VB code to give each category a colour ie BH will turn out an orange colour.The problem occurs with the summary sheet.It takes the data from the employee worksheets and uses the same VB coding to change the categories to the appropriate colour.The data the summary receives is correct but the colours won't activate until I double click the cell.

Is there something I'm missing?