I doubt they'd get anywhere. These things are based on pre-set rules and argued and mediated on by lawyers. The colour of the jersey isn't a factor.
On the other side of the coin, how is N'tamack's hit the same punishment as Ringrose's? Ringrose mistimed a rush and made head to head contact that he was trying to avoid (wrapped and had a knee on the ground at impact). N'tamack shoulder charged a prone player to the head with no wrap.
Rules are rules and France's set up worked against them here, an Italian Benneton player probably gets Ringrose's treatment and an English player N'tamack's.