What livery was worn on the date before 1936, with the description of Gresley RF?
CREATE TABLE "list_of_great_central_railway_locomotive" (
  "number_name" text,
  "description" text,
  "livery" text,
  "owner_s" text,
  "date" real
);
SELECT "livery" FROM "list_of_great_central_railway_locomotive" WHERE "date"<1936 AND "description"='gresley rf';