I haven't read everyones comments, but many have commented on their surprise when the grey looks blueish or brownish. I just took a 3 day course on fabric dying and we tried to mix grey. Not as easy as you would think using primary colors. There are 3 or 4 different black dyes which are available, some have a blue cast, some a green cast and some red. As you dilute them to make grey, the underlining colors are more predominant. So analyze all grays, are they warm or cool?