Button to colour cell/s (but no VBA?) How is this done?

Hi there

i have come across this spreadsheet which has a button which allows you to change the colour of cells quickly....but how the heck is it done? i just dont see any code behind it!

i tried opening the spreadsheet and the buttons didnt work, i suspect that the code behind it is sourced from another linked object which you didnt include.

there is code but it is in another workbook, so the buttons don't work unless the other workbook is present