The purpose of the stylesheet hack was to provide a default without having to use inline styles on containers. We can do this much more neatly by instead just giving the inline styles to a parent container, leaving users free to customize the children.
The axis color now controls the color of the axis line, instead of its ticks and labels, while the tickColor controls the tick color. This makes a little more sense and provides the minor feature of being able to change the axis line color separately from that of its ticks. Pull request #917 ought to be easier to merge now, too.