It should be easy, but it's not. For some reason, all the sale yarns (which change every Thursday) are horribly displayed, with color samples the size of Chiclets. Sometimes they give you the manufacturer, yardage, gauge, sometimes not. Our good friend Benne sent them a scathing email about it a while back, and they got better. But they aren't great at displaying yarn. You'd think their specialty was hardware or something.
Yesterday, I searched their sale pages ONCE more for a few extra balls of Solista. Did an entire site search. No luck. Then I remembered that Herrschner's sometimes hides its yarn in plain view. So I did a search for the colors. Here's a good example-
Using the search term "yellow and white", I found a picture of Solista-and the following description-
Yellow and White: "Yellow and White"
Yellow and White
Item #: YY710925-1142
Notice that there is no description of the yarn, and the name isn't given at all. Searching by the item number does not yield results. The photo of Solista and that itty bitty swatch tell it all. The verifying indicator is that Yellow and White's stock number matches Yarndex's color chart, which shows that Solista yellow and white is color number 1142. All colors of Solista are in stock, but I had to trot over to Yarndex to get a good color list, because Herrschner's had not linked all colors of the same yarn in a group. You must stumble on them one by one.
I learned about the Herrschner's oddities last year when we all fell in love with Paton's Katrina. There was a swatch, and all it said was 'black'. The price made me do a double take. So I took the item number over to Yarndex, and found that the item number had common elements with the black Katrina.
Similarly, two weeks ago, there was a listing for Brilliant Black. I did a bit of searching for Brilliant Black. As it turns out, the listing was for Paton's Brilliant. I checked this morning, and a search for Brilliant Black brings up a picture of a purple ball of Brilliant.
Hope you find this helpful.