As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EQUIPMENT SUPPLY COOLING ALTERNATE LIGHT CAME ON IN FLIGHT AND EFIS SCREENS WENT BLANK (LOST COLOR). COLOR CAME BACK (LIGHT WENT OUT), FOLLOWING RETURN TO THE AIRPORT. *S/D* FOUND ORIFICE ASSEMBLY MISSING FROM EFIS COOLING SUPPLY DUCT. INSTALLED MISSING ORIFICE ASSEMBLY.