I've never been given the opportunity to speak to the senior grader. In my opinion, I don't think SGC recognizes that there was a pink color pass separate (and prior to) the red color pass. I believe that they are concerned that the pink that displays is faded red. I even gave them my SGC 40 as an exemplar to compare with that red color shift and they still said no. I'd really like the time to be able to definitively research which colors were used in which order. I've seen several cards with color shifts that reveal the "mixing" of colors.
In the following thread, Jamie has a card that appear to only have yellow, brown and (in my opinion) buff. Look closely and there is a right shift of the buff revealing a separate yellow pass, but an orange background. Krueger looks ghostly from the missing pink and obviously the missing red background. Chris also has a lithographic print in the thread that shows separate red, buff and pink. Essentially, just because the color looks red doesn't mean that it wasn't mixed/layered with other colors.
http://www.net54baseball.com/showthr...ight=pink+buff
Below is a scan from a card IrishDenny had on eBay (hope that he doesn't mind that I stole the scan). It shows a fairly dramatic vertical pink shift. In my opinion, orange is a mix of pink and yellow. The Stephens does have red on the cap, mitt and undershirt. Notice that the red on the cap is in no way shifted, and thus I conclude a separate color pass from pink. I also think it demonstrates that pink was one of the last colors, with red being the final color.
Again, all my opinion, and I understand that they have to stand behind every card they slab. At the moment, they aren't comfortable doing it.