how to differentiate male and female drawf Gourami and Cobalt (Powder) Blue Gourami

[Beaumont]

hi all... i recently juz bought 2 drawf and 2 cobalt blue gourami for my community tank.. juz wonders do i know they r males or females.. cos in the aquarium shop each one of them juz look the same ~~...

 

[Lotus]

Females are a duller brownish color, males are blue.

There's a pic of male and female here: http://www.solodvds.com/breeding_dwarf_gourami.asp