16.10 Coloring days
It is possible to add colors to some days.
@startgantt
Project starts the 2020/09/01
2020/09/07 is colored in salmon
2020/09/13 to 2020/09/16 are colored in lightblue
[Prototype design] as [TASK1] lasts 22 days
[TASK1] is colored in Lavender/LightBlue
[Prototype completed] happens at [TASK1]'s end
@endgantt
