Hi Raheel,

My blog here should guide you on how to colour items when selected by a parameter: https://interworks.com/blog/mliu/2018/02/08/questions-tableau-training-colouring-specific-columns-and-rows-crosstab/

However I'll also write instructions on how to do it for the bar chart: First you create your parameter, in my example I have used market here:

Next I will create a calculated field which:

So every time a market matches the market in the parameter, it will give it a value of 'Colour'

Finally put this colour field onto colour on the marks card. Then you should get the view you're looking for! I've attached the workbook if you want to see what I've done:

Thanks,

Mavis