I retouched my blue and ended up using Teal for underneath since I ran out of Sky Blue dye. If going for an aqua color and choosing between the Aqua and Teal dye, go for the Teal. It's been in for 2 weeks now and it hasn't changed colors quite yet but barely entering it's green stage. I left the dye in over night with a shower cap and maybe that enhanced the colors all around. Definitely buy more than less boxes of dye when using any of the blue colors because it will be quite evident when you miss a spot on your head. The teal is more pigmented and has less of a contrast compared to sky blue and blends better.
Hope your weekend's been well.