Stash enhancement

I went to Rowan store this morning and got some cotton yarn for next big project - Babette Blanket. I will use some from my stash for white, beige, navy, light blue colors. I was looking for dark brown color but it was not in 4ply cotton, so I selected Cotton Glace instead. But this idea was too optimistic. I tried with small motif using 4ply yarn plus Cotton Glace yarn and found the fact that thickness of each yarn were completely different. It doesn't affect on scale but the touch of the fabric is somewhat hard. So Cotton Glace will not work for this project. Anyway, this is not the project that have to be worked in hurry and I need some more color.