In the link below are three more color conceptions of the logo and the first one without that gray border at edges of the image.

https://imgur.com/a/gnDlpxi

I made a third concept of bismuth logo. In this case I have redesigned the current logo. This one is more minimalistic and more in favour of modern logo design. I have some more colour variations of this concept but I can post only one. I think current shape of logo is too characteristic and original to be completely changed.

Hi. Here is my second idea. Colors of course can be changed:

Hi, here is my suggestion. I know that some currencies use similar cubic / hexagonal shapes in their logos. I used that shape because figure like this reminds of some crystal structure. I think I also met the rest of mentioned criterions.