You want non Feritic Stainless Socket cap screws (Allen Key).
Which you can buy from a good Engineering tool shop.
They wont cost much just take a sample to match.
Paint the heads with enamel paint what ever colour you like!
Run a tap down the screw holes to clear out old locking compound and any damaged threads use a good lock/seal compound(loctite thread seal) and torque them down to the correct setting.
you can down load Unbrako's screw torque charts or ask the guy in the shop
