fix the color of the hover for the next/prev/close buttons in the quick tour (#1553)
fix the color of the hover for the next/prev/close buttons in the quick tour (#1553)


all-of-us/workbench,all-of-us/workbench,all-of-us/workbench,all-of-us/workbench,all-of-us/workbench,all-of-us/workbench,all-of-us/workbench,all-of-us/workbench,all-of-us/workbench