For high-contrast, you can choose a dark color like purple or dark brown/chocolate. For a more neutral look, white or cream looks good, or even champagne. Sort of depends on the time of day or occasion...
Metallic is a great idea, but for some special occasions such as a wedding. However, if you want a go-to combination for work, I would suggest seashell heels.
You can wear heels if it is normal dress or frock then you can wear heels on it.