In Asia teas are classified according to the colour of the infusion
rather than leaf colour. Hence black tea is red tea and pu-er tea is
black tea (if your pu-er is red then you probably aren't brewing it as
strong as in Asia - try brewing it gongfu style).

As for why oolong is known as blue tea, i think the reason is that the
wuyi oolongs were traditionally baked over charcoal fires and the leaf
attained a metallic tinge, reminiscent of the colour blue. But that
goes against the other labelling system. Can anyone shed some light?

tea ja vu, perth, australia