When MnO2 is fused with KOH a coloured compound is formed. The product and its colour are
K2MnO4 Purple green
MnO2 is oxidised to K2MnO4 in alkaline medium to acquire a stable oxidation state of +6
2MnO2 + 4KOH + O2 → 2KMnO4 +2H2O
The colour of the solution is light purple green.