If it's bone dry and scorching sunshine

you would only need worn yellow's. New ones offer sooo much grip in the dry
If there's any hint of moisture

whether that be from rain or frost you will require new greens sometime during the day or at least a couple of sets of lightly worn ones
And don't forget:
As previously posted, to assist us with the booking in process, if any drivers, who may not have attended EPR previously and would not, therefore, be part of our database, are thinking of coming to any future meetings, it would assist us greatly if you could PM the following details:
Name, Senior or Junior, Class, BRCA No., PT No., Frequency or Frequencies and Formula (if known).
Many thanks,
EPR Committee