How many locomotives have a livery that is highland railway green
CREATE TABLE "locomotives" (
  "no" real,
  "name" text,
  "livery" text,
  "locomotive_type" text,
  "wheel_arrangement" text,
  "builder" text,
  "year_built" real,
  "status" text
);
SELECT COUNT("name") FROM "locomotives" WHERE "livery"='Highland Railway green';