Perhaps you use calendar color-coding for one dimension (e.g. people), and you need a way to visually distinguish another dimension (e.g. task type, or location).
Here are methods to color-code across two dimensions with Teamup.
Assign the event to two calendars
Create one set of calendars for the first dimension (e.g. team members).
Create another set of calendars for the second dimension (e.g. location).
When you create an event, assign to the appropriate calendar for each dimension.
The event will be striped with the colors of both calendars, like this:
Use color blocks in a custom field
If you don't want to use multiple calendars, or don't like the striping effect, here's an alternative method:
Create sub-calendars as needed for the first dimension (e.g. team members).
Make the field contents visible in the event title.
Now you can use the color-coded calendars for team members, and the color-coded custom field for task types.
Tip: customize the About box (in the left sidebar) to show a color-code reference.
Color-code without using calendar colors
The unicode color blocks work well if you want a more minimal look but still need to color-code some aspect. Or, if you want color-coding for one dimension but not on the calendars themselves.
Create sub-calendars as needed for the first dimension (e.g. team members). Make all these calendars the same color or similar shades.