Because this example specifies a sparse map, colocation_name defaults to db1_tableop1, which overrides the colocation name specified, if any, when the table operator was created.
SELECT * FROM db1.tableop1 ( ON ( SELECT * FROM tab1) PARTITION BY col1 ON ( SELECT * FROM tab2) PARTITION BY col2 EXECUTE MAP = OneAMPMap USING myvalue(10,20) ) AS d1;