Transition metal colours

• [Cu(H2O)6]2+ is a pale blue solution
• Cu(OH)2 is a pale blue ppt
• [Cu(H2O)2(NH3)4]2+ is a dark blue solution
• CuCl4 2- is a yellow solution
• Reduction of Cu2+ - White ppt of CuI and a brown I2 solution.
• Disproportionation of Cu+, Brown solid of Cu and a blue solution of Cu2+
• CoCl4 2- is a blue solution
• [Cr(H2O)6]3+ is a pale purple solution that appears green due to impurities.
• Cr(OH)3 is a dark green ppt
• [Cr(NH3)6]3+ is a purple solution
• [Cr(OH)6]3- is a dark green solution
• Cr2O7 2- is an orange solution
• CrO4 2- is a yellow solution
• [Mn(H2O)6]2+ is a pale pink solution
• Mn(OH)2 is a pale brown ppt
• [Fe(H2O)6]2+ is a pale green solution
• Fe(OH)2 is a dark green ppt
• [Fe(H2O)6]3+ is a yellow solution
• Fe(OH)3 is a orange/brown ppt
• MnO4 -/Fe2+ -> Mn2+/Fe3+ goes from purple to pale pink
• I-/Fe3+ -> I2/Fe2+ goes from orange/brown to brown