Glad to hear the winnowing is going well. I was going to recommend Duluth Trading too, as a lot of my 'gear' items are from them and Eddie Bauer. I work seasonally at a farm/orchard and I found that jeans aren't great unless it's quite cold - cargo pants or pants like the dry-on-the-fly ones (Eddie Bauer makes some too, and capris and shorts) are much more versatile and comfortable. Black and navy are too dark and show stains but anything in the olive/tan/light brown family works well. Comfortable shoes/boots, again in earth tones, and wicking socks, and layers on top (this is where hoodies really shine) and you're set. I very much agree with the advice to make sure your colors are ones you like and flatter you - if you're in wicking pants and a tee 40+ hours a week, at least make sure they are in colors you enjoy.
I feel like a great deal of the appeal of the wardrobe in the linked article is that she wears so much white and pastel all year round. If her jeans were blue and her tops were charcoal, say, it would look much less fresh and interesting. I think the general principles are good, though.