reporting services - highlight the duplicate row values with background color in ssrs report -

im trying highlight row duplicate values depends upon count in specific background color.

for example.

if no. of duplicate values 2, bgcolor in "green".

if count 3, bgcolor in "red".

i need expression process.

any help!

say have simple data this:

if i'm setting highlighting based on id, make sure group based on column, e.g.

then, backgroundcolor property use expression like:

=switch(count(fields!id.value, "idgroup") = 3, "red"     , count(fields!id.value, "idgroup") = 2, "green") 

so each detail row, count id values in id group , set colour accordingly. works data: