Oxalis with purple leaves

Hi there. I've had this great, easy to grow plant forever, but I've never known the correct name for it. It seems very similar to the Oxalis (Wood Sorrel) that I have but the leaves are a purple color and more triangle-shaped than the Oxalis. The leaves are bigger too. The flowers, which are just like Oxalis are a light purple. It grows from the same bulb type things as the Oxalis too. I've tried and tried but I can't seem to find anywhere online that talks about a Purple-leaved Oxalis variety. Can you help me out? Thank you, Alicia