[kuromi]

Fe3+(yellow)   +   NCS- (colourless)     <->   FeNCS2+  (blood red)

 when i add one more drop of Fe3+ solution into test tube
and one more drop of NCS-solution into other test tube

explain why  added Fe3+ solution is blood red while added  NCS-solution is reddish dark ? 

By le Chatelier's principle , the equilibrium position shifts from left to right when conc . increased .  why  the colors are different ?
 

[BluRay]

Fe(SCN)²⁺ is not the only compound formed. There are also Fe(SCN)₂⁺ and Fe(SCN)₃ and they probably are of different colours.

[Astrokel]

Think about what happened to the other reactant and the end result of the combination of colour when you adding Fe³⁺ or thiocyanate.

[kuromi]

thank you for your ans.