Ti+3 is purple, but Ti+4 is colourless. This is because
d1 configuration of Ti+3 and d0 configuration of Ti+4
d1 configuration of Ti+3 and d10 configuration of Ti+4
d0 configuration of Ti+3 and d1 configuration of Ti+4
d10 configuration of Ti+3 and d1 configuration of Ti+4
Color is due to presence of unpaired electron
The electronic configuration of Ti is 1s2 2s2 2p6 3s2 3p6 3d2 4s2 and it represents
Ti3+ is purple, but Ti4+ is colourless. This is because:
The electronic configuration of Ti is 1s2 2s2 2p6 3s2 3p6 3d2 4s2 and it represents: