The visual design of cards on a wall

Agile teams put cards on walls and boards.

I wonder though how many of those teams understand that the purpose of visual management is to make problems obvious.

How easy is it understand the board?
Can you read the cards from a distance?
Can you read the cards at all?

Mundane details like large and legible lettering, consistent colour coding, vertical positioning for importance, etc. are quite important.

The purpose of visual management is to make problems obvious.  How well is the visual design of your Kanban board / card wall / task board fulfilling that purpose?