I recently made a batch of soap using rooibos tea. I just replaced the water with a strong brew of tea, but it had very little affect on the color. It came out a yellowish color similar to the other tea soaps I have made (Nettle tea and a White Ginger Tea). The next time I will add a color such as a red or pink clay or maybe paprika to get that reddish color. But I just past the six week mark and used it this morning. It's not the color I intended, but it's a great soap.