If you try adding ?:render=false (i.e. http//server-name/site/workbook/view/sales?:render=false) to the URL does the viz appear correctly? Also, if you edit the color palette to be in line with the colors you want, do the changes stick?
There's been a few threads about colours changing on publication to server such as Conditional Color Coding logic misbehaves in server and this one Colours keep resetting which suggests Tableau have it as a known issue (ID 545760), though its not yet listed on the Known Issues | Tableau Software page.
So its a bug.