The (B − V) vs. (V − H) colour selection window adopted in the present paper (right) along with the commonly adopted one based on the (V − Z) colour (left). Blue filled squares and lines are for a CB07 LBG model with Z/Z_⊙ = 0.2 and Age = 100 Myr at increasing redshift and E(B − V) respectively. Models having solar metallicity and Age = 100 Myr and Age = 300 Myr are represented in magenta (crosses and long-dashed lines), and red (empty squares and short-dashed lines), respectively. Red and green points indicate lower redshift passively evolving and dusty star-forming galaxies, respectively. See main body for details.