Ti 2+
violet
Ti 3+
purple
V 2+
violet
V 3+
green
VO 2+ (+4)
blue
VO2 + (+5)
yellow
Cr 3+
green
Cr2O7 2- (7+)
orange
Mn 2+
v pale pink / colourless
MnO4 2- (6+)
green
MnO4 - (7+)
purple
Fe 2+
green
Fe 3+
yellow
Co 2+
pink
Ni 2+
green
Cu 2+
pale blue
[CuCl4]2-
yellow
[CoCl4]2-
blue
[Cr(H2O)6] 3+
green
[Cr(NH3)6] 3+
purple
[Cu(H20)6] 2+
light blue
[Cu(NH3)4(H20)2] 2+
dark blue
Cu(OH)2
blue
Fe(OH)2
green