Random particle shading not truly random

Hi everyone,

I am having a problem where I am trying to randomly colour particles from a gradient. In the gradient node, I selected gradient output and random colour selected in Primitive Emitter node. However, what I am seeing the gradient mapped across the shape of the emitter. Even with randomness and offset cranked up all the way up I can still a bias across the particles, i.e. particles emitted from specific points in the emitter having one colour as opposed to truly random from across the whole gradient.

So my question is, how do I achieve true randomness selecting from a gradient of colours?

Thank you!

Update: Unticking ‘Repeating random’ in primitive emitter node eliminates any bias.