Four of the following five are alike in a certain way and hence form a group. Which of the following does not belong to the group?

Only three boxes are kept between Olive coloured box and box number 321 Only two boxes are kept between Olive coloured box and Black coloured box Black coloured box is kept somewhere below box number 321 Purple coloured box is kept immediately below the box number 325 Purple coloured box is kept at one of the positions above box number 321.. Only two boxes are kept between box number 251 and Mustard coloured box Pink coloured box is not the topmost box. pink coloured box number is not 211. Only two boxes are kept between Pink coloured box and White colour box. Only one box is kept between Black coloured box and the box number 211... There is only one box between Purple coloured box and the box the number given to which is less than that given to Purple coloured box. The difference between Mustard coloured box and the box immediately below it is less than 80...