how to use schema with data type

I have tried to use a user defined data type I created within a schema.  
But I could not figure it out.

CREATE OR REPLACE FUNCTION xchromasun._chromasun_totals(date)  RETURNS SETOF xchromasun.weekly_mpr AS

CREATE OR REPLACE FUNCTION xchromasun._chromasun_totals(date)  RETURNS SETOF "xchromasun.weekly_mpr" AS

I had to move the user defined data type to "public".

Could someone explain how I might get that done - that is use a schema 
data type from a function.

I'm using 8.4.x.

Johnf