What is the color code with a temperature classification of ordinary?
CREATE TABLE "operation" (
  "maximum_ceiling_temperature" text,
  "temperature_rating" text,
  "temperature_classification" text,
  "color_code_with_fusible_link" text,
  "glass_bulb_color" text
);
SELECT "color_code_with_fusible_link" FROM "operation" WHERE "temperature_classification"='ordinary';