You don't need to be as worried about thiosulfate in color negatives as there's no residual silver, just dyes. So no need for archival washing like black and white.
Welcome to Photrio.
As a matter of fact, you want to avoid wash-aids and wetting agent with colour negatives.
You want to use instead something like Kodak Final Rinse, because of the bactericide in it.
And it should be the last solution used - after the film is washed.