Did a transmission fluid change and a month later its dirty

Hello, transmission fluid servicing on a Honda product is always "drain and fill". On a Civic like this, this means you can only really drain 2 1/2 - 3 quarts of fluid and refresh it with 2 1/2 - 3 fresh quarts to "fill" the transmission. The transmission holds just less than 6 quarts of fluid in this model. The fluid should be served when the "Minder 3" indicator comes on, which is about every 30,000 - 40,000 miles -- approximately. If it has not been serviced regularly like that over the 12 years of life the vehicle has had, it's possible it could take several "drain and fills" to keep the fluid more clean. That said, "dirty" for me would be brown or black -- what is yours looking like? Are you using Honda ATF DW-1 fluid? Nothing you can do to go back in time for the previous owner's maintenance -- just do your best going forward.