Version 2020.01 improves the Appearance Options to allow specifying different background colors based on days of the week. In the previous version, only the date number colors could be specified. You could set background colors on dates, but you'd need to do this manually for each date. There was no easy way to assign a background color for all dates, based on the day of the week.
To set background colors based on days of the week, check the box labeled Color dates based on day of the week on the Appearance Options window. Next, click the Day Colors button.
By default, weekends will have red date numbers and all days of the week will have a transparent background (or the color specified in the selected appearance theme, which is light gray when using the default appearance theme).
To select a different color, click a cell in the Date Number or Background Color column. A drop-down will appear. You can select a predefined color from the list or specify a custom color on the Custom tab.
In the example below, weekends were configured with orange date numbers and yellow backgrounds. Friday was configured with a bright blue date number and light blue background.
After clicking OK on the Day Colors and Options windows, the Month view will update to color all dates based on the specified colors.