The last part got scrambled, should read like this:
(...)
Use it like this:
SELECT * FROM foo WHERE foo_id > myval();
Or, for the case at hand, an example in sql:
CREATE FUNCTION my_colors()
RETURNS text[] AS
$$ SELECT ARRAY['red','green','blue'] $$
LANGUAGE 'sql' IMMUTABLE;
Use it like this:
SELECT * FROM foo WHERE color = ANY(my_colors());
Regards
Erwin