question about access custom enum type from C

Hi, when I’m trying to access values of my custom enum type I created with

create type colors as enum ('red', 'green', 'brown', 'yellow', 'blue');

I’m getting oid as 16387 and I can see it stored as a chars

is number 16387 is always OID for enum type?

if not how I can get information about type of the result if it’s custom enum type

thanks in advance

dm