get-style-delta in drscheme:language:language<%>
The style delta that this method returns is used in the language dialog and the DrScheme REPL when the language's name is printed.
When it is #f, no styling is used.
If the result is a list, each element is expected to be a list of three items, a style-delta, and two numbers. The style delta will be applied to the corresponding portion of the name.
( -> (union #f send a-drscheme:language:language get-style-delta)
(instanceof style-delta%)
(listof (list (instanceof style-delta%) number number)))