This is particularly pertinent to V8 now that we are able to float sheets on top of others in dashboards. We should be able to set the background shading to none, equaling transparent, not the shading of the background. It would also be handy when exporting EMFs to PPT etc. and you want the background to disappear (you can ungroup an EMF but this would be easier).
Possible Duplicate Ideas (Added By Sean Boon)
*Community Manager Update: This feature was released in 2018.3 - Read more about 2018.3 in the release blog: Heatmaps, set actions, new dashboard formatting, and more—now available in Tableau 2018.3 | Tableau Software
Thank you! Amanda Boyle