Roundhead cock x asil hen = roundheadasil, this is so because most offsprings inherit the looks of the mother....if the cock was prepotent and had an offsprings that just look like the father then they are called asilroundhead....this is how we select and name the offsprings of a 1/2 x 1/2 mating.
If the female offsprings are being backcross to roundhead (father), we called the offsprings as Asilroundhead because the fractional distribution of blood would be heavy on Roundhead.
On Brood Materials having different leg color, for example a greenlegged Hatch Cock x yellowlegged Hen Sweater.
We select the 1/2 x 1/2 offsprings according to leg color.....if the offsprings are greenlegged then we call them SweaterHatch, whatever the comb it gives....and if the leg color was yellow we call them HatchSweater, whatever the comb is.....
if legged color was YellowGreen we now then look at the comb...if the comb was straightcomb we call them SweaterHatch and if the comb was peacomb then we call them HatchSweater.
If we backcross the female offsprings to Hatch Cock (father) we call them SweaterHatch because the hatch blood according to our record contains the higher blood donation, inherited by the offsprings no matter what the kind of comb or color of leg.
On your case....Lemon and Sweater are sometimes hard to distinguish on it's 1/2 x 1/2 crossbreeding....but we know that most Lemons are Straightcomb and Sweaters are Peacomb.
If the offsprings are straightcomb we call them SweaterLemon and if the offsprings are peacomb we call them LemonSweaters....what ever leg color they may give (white, lightyellow, yellow).
There are times that we used broodmaterials with both equal on legcolor and type of comb but differ in bloodline....and we really have a hard time to distinguish... we used the feathercolor, body conformation, height and kind of fighting style.
Sometimes if Feather is dominant on our 1/2 x 1/2 mating like for example a Gold cock x HatchHen.....if the offsprings are having Gold tail, goldWings or gold breastfeather they are called HatchGold, whatever the kind of comb or legcolor....and if no Gold feather appears they are called GoldHatch.
On BlueCock x GreyHen.....if feathercolor blue appeared on breast, wings and tail...they are called BluePyle if dominant color was on Blue, and.....GreyPyle if Grey feather color was dominant over blue.
With todays modern kind of distinguishing a bloodline is by using the toe markings, nose markings, legband, wingband and other method of putting a breed I.D.....they do this because it's hard to distinguish nowadays if it's a YLH, Radio, RoundheadClaret, Kelso or Sweater....which they almost look alike because they are relatives....not only that because nowadays there are variety family on hatch, roundhead, Grey etc...having a different blood composition but was considered to belong on a Dominant blood contributor.