The Inhibitor of Gold [ig/ig] is a very weak dilutor of pheomelanine (red pigment). It will not remove 100% of the red pigment on the wing bay of the wild type males. It will not even remove 100% of the pheomelanine in the hackles feathers of the females and males or 100% of the pheomelanine in the saddle feathers of the males. It leave the hackles and saddles on the males an off white color called cream.
In non-barred breed with cream varieties like the Dutch Bantam and the Cream Light Brown Leghorn varieties found in many countries (but no SOP in North America) the goal of exhibition breeders is to get the Cream color as rich as possible. This requires that minor genes for red color enhancements that are found in the Gold Crele varieties be retained in the Cream Lines. If they are lost you get a very dull and washed out colored bird that the Dutch Bantam breeders call a Dead Straw color and consider an extremely poor quality bird. The same thing happens in the self blue color varieties (Andalusian, Lavender) when the the minor eumelanine (black pigments) getting bred out due to poor selection of breeding stock. I see advice all the time on the poultry forms that you have to cross you Cream Light Brown birds back to wild type birds every 3rd generation to keep the color from fading or that you have to breed back your Lavender birds to Exteded Black birds every 3rd generation to keep the color from fading. That makes me cringe every time I hear that. The back cross ruins your line. Silver Dunn who wrote the book on breeding Andalusian Blue would only breed blue cockerels who came from a Blue x Blue pairing because he could see all the tells for the minor colors in a Black or Splash bird. He would use a Splash or Black pullet if they had superior type most Black and Splash cockerels has no use to him in his breeding plan. He said they would ruin a good line. The Dutch breeders can Cream Light Brown Birds that come from a Gold Duckwing out Cross Swavers. I don't speak Dutch so I don't know what that means, but they claim that a Dutch Poultry Judge can immediately tell a well breed bird from Cream x Cream breeding from an Out cross to a Gold Duckwing and that you can't get exhibition color for an out cross to a Gold Duckwing. They saw you have to use Cream X Cream Pairings and that outcrossing to Gold Duckwings will ruin the cream color in a well breed line.
So....The question begs why do so many of the show lines of Cream Legbars breed out all minor pheomelanine colors form their lines? They really have over shot the marker. The cream gene (inhibitor of gold) will dilute the chestnut on the wing bay of the males to where you can see patches of cream coming through but will leave a smudgy red on the shoulder. The hackles of the hens and the hackles and saddles of the males should not be a white color but rather a cream color. If they saddles of your males are not cream you have a Dead Straw base color and not a Lemon, Citric, or Cream Base color.
Just my two cents on cream.
Below is a Cream Leghorn that I grew out. He was a Sport from a Single Combed Light Brown Leghorn line from a Hatchery so is is a "Swaver" and not an exhibition quality cream color.
Here is a wing of a Cream Legbar (photo credit to BlackChickens13) You can see that the Cream has diluted the color on the wing bay but the by itself Cream is not strong enough to remove the chestnut. I
Finally here is a Cream Legbar Cockerel that I bred. I put some silver columbian hens in the photo with him to show that Cream is a weaker dilutor of pheomelanine than silver is and that Cream birds should NOT look silver. This guy does not have a Dead Straw Base. He has the richest cream I could get.