Here are a range of the Detective Comics covers, with original DC Comics cover in brackets.
Mimosa Detective Comics 1
24 pages, full-colour, newsprint stock cover and interior pages, +/- 1959 - possibly first series.
Cover of Issue 1 (Detective Comics 269), courtesy of Mahdi (Readers Den Comic Shop):
Cover of Issue 4 (Detective Comics 283):
Mimosa Batman Newsprint Series