Hi I have a requirement wanted to color grey for Total and Grand Total is there any workaround.

Possibly. There is a hack using SIZE() to treat totals and grand totals differently, but you have partitions that only contain 1 value, the same as totals, so the hack wouldn't work. You could do something like UNION your data to itself, but for the sake of having a background colour on a row, I consider that a poor reason to double your data size. One other option is to use a small scaffold to allow the use of the data twice, instead of the UNION, but you'd have to use the placeholder method to get a whole row shaded. I can't be bothered to do it here but describe some ways, including the placeholder method, of highlighting rows here:

Three and a Half Ways to Conditionally Format Tables (including the headers) in Tableau