White does not dilute, so it will not blend the colours. Other genes present in the white bird might, but without breeding records, you won't know whether these genes are present or not. Once you have offspring, you can learn something about the genes that that particular white is carrying based upon the results. If you get any solid whites, then the non-white is carrying a copy of recessive white. If you get any with blue, then the white is carrying blue. If you get any with good mottling, then the white is carrying mottle. Etc.