OS X Finder has this nice feature to colour-label files. I'm thinking of using a similar feature in my app (that is: use this in an NSTableView/NSOutlineView, not looking to highlight items in Finder from my app). Is this ability somehow available through any of the default user interface classes or would it require a custom implementation?
I have experimented with setting NSTextFieldBezelStyle to NSTextFieldRoundedBezel but this seems to kill the ability to draw a background colour and also defaults to a grey border.
Have a look at the NSURL NSURLLabelColorKey, which is one of the attributes you can set for a URL. You can set these values with setResourceValues:error:
After Edit: Sorry, I misinterpreted the question. I think the easiest way is to use a view based table and put a borderless label inside an NSBox of the custom type. You can give the box rounded corners and a background color with no border, and that looks just like the finder label.