Default value of column not respecting character length or domain restraints.

It seems I can feed a default value to a domain that won't fit in the
underlying base type. I have the domain html_colors as so:

CREATE DOMAIN html_color AS char(7) CHECK (VALUE ~ '^#[A-Fa-f0-9]{6}$');

I then defined a column of html_colors as so:
ALTER TABLE users ALTER COLUMN profile_color SET DEFAULT '#FFFFRFF';

This worked fine and I didn't notice it until I added arecord to the
users table and got the error:
ERROR: value too long for type character(7).

This behavior seems undesirable to me. Is this a known bug or is there
a reason for this?

Regards,
Justin Dearing