Hi KRLyric,
I’m afraid it isn’t possible to dynamically modify or update a widget style, but I’m going to be logging both points you mention so our team can evaluate them as feature requests.
To a degree, you may be able to simulate the interactive effect by dynamically setting an existing widget style onto a widget–for example, by using Interaction Styles:
https://www.axure.com/support/training/interactive-button-tutorial
Alternatively, using Dynamic Panels may be more scalable as you try simulating this with a handful of predetermined states.
In using this DP approach, you could set up a few walkthroughs that include differently colored panel states that can be built to reflect the hex inputs, which you may specify beforehand to the end-user for demonstrating the idea of the prototype. If you’re unfamiliar with IX styles in the tool and/or using dynamic panels, please let me know and I’ll be happy to elaborate further. Nevertheless, I’ll also be logging these current limitations so our product team can evaluate alongside your workflow. Thank you!