Yellow: the least popular color in 40K

I am referring to the Imperial Fists space marines.  I have a project I was thinking of starting this weekend (but didn't) in which I paint up one good model from various chapters to make up Pedro Kantor's Honor Guard squad (I call it Operation: Royal Flush or the Royal Flush Gang -- just don't tell DC comics that).  So I was looking in the SM Codex for inspiration, and you know what?  The only IF model in the whole book is Captain Lysander. The whole damn space marine codex.

AND I just came from Barnes and Noble and was perusing the BL bookshelves, and saw "The Architect of Fate" which shows the drawing of an Imperial Fist marine on the spine, indicating it is probably in the battles series featuring that iconic chapter, right?  But the cover shows no IF marines that I can see!  The main feature is a Changer of the Way and a lot of shadow-shrouded and dead-looking marines, but I don't see a damn shade of yellow on there at all.

Is this chapter so unpopular that GW can't risk low sales by showing them on the cover art of their own book??  Or feature all the painted glory of said chapter--a FOUNDING chapter by the way--in the codex itself???  Seems pretty ridiculous.  Maybe it's that, like the Ultramarines (though they do get the most glory), the Imperial Fists are so generically space marine that they just don't attract much attention from fans.  Of course, if you google them for images you'll find plenty from hobbyists who disagree (fortunately for me and my research).