If you are asking how to clean this pigment off of the column, the answer depends on the nature of the pigment. Sometimes it will wash off with high salt, although it may be a gradual process. Sometimes it will be necessary to use an organic solvent, like ethanol, to dissolve it off the column. If it is not bound to the column but just clogging it, then you might be able to get it off by running the column flow in reverse.