Compared with some other oxides, you do need to add more of this to get the desired effect. And no matter how much you add, it won't ever give you a deep purple. I don't consider this to be a "defect" of the oxide -- that's just how it works. But be aware, if you're looking for a wizard-robe purple, choose a different colorant or blend.
The pretty lavender color is great for floral scents. I like to use it with sage and white, too.
Like the description suggests, you can achieve a vibrant, cool-hued purple in CP soap using this colorant with a little bit of ultramarine blue oxide pigment; it really electrifies it and oomphs up the color! And then to that, you can add tiny amounts of activated charcoal to go into deep-cool-purple territory. I think this combo looks great as a drop swirl within a lighter or uncolored soap.
I have noticed you have to use more of this colorant to achieve a deeper purple than you do the other oxides. That said, it's very pretty, doesn't fade, and is easy to use in CP soap.