Is it permitted to wear shoes that have a little of gold on the heal?
It is wonderful that you are correctly sensitive to the ideas of tznius.
I think the question should be reworded to say is it correct or incorrect to wear shoes with some gold on the heel. The reason is because we can’t say that it is outright not tzanua, as your foot is covered. However, the color is perhaps calling and attracting undue attention to oneself. This would depend on the local customs, and your question should be asked to the local Rabbonim.