Colour-wise, if your monitor is calibrated to display sRGB correctly it shouldn't be too far off (XD is not colour-managed though)
Could you please share the sample file.
I need some more details.
1. Is it exported from desktop or web
3. Which browser is used to preview the exported image.
Thank you for reaching out. In addition to what Kenneth and Jose has mentioned. I would request you to please see this page created on how to export assets with better quality: https://medium.com/thinking-design/protip-exporting-assets-in-adobe-xd-c586996de703
Let us know if that helps.