Hi, have you tried using the groupcolor keyword argument?
For example:
errorline(x, 2*y[:, :, 1], errorstyle=:ribbon, label="Ribbon", groupcolor=:red, secondarycolor=:pink)
errorline!(x, 1.3*y[:, :, 2], errorstyle=:stick, label="Stick", groupcolor=:blue, secondarycolor=:cyan)
errorline!(x, y[:, :, 3], errorstyle=:plume, label="Plume", groupcolor=:green, secondarycolor=:lime)