Say, I have a table Categories. On a page I have a header and for each category the colour of a header varies. A colour is of the presentation level and I've heard that what's related to the UI/presentation level shouldn't be stored in a database.
There must be exceptions. However, in this case I figure that a colour indeed shouldn't stored in a database.
Then there - in a config or in code? How will that make a difference, why will that be better?
In general, what do you make of this rule?