Incorrect colorization, indent, and font size for outputs when set_display(ascii) is in effect

[robert-dodier]

Copying and condensing from #2005 in order to focus on the unsolved problems.

When set_display('ascii) has been called, output cells are colored by "ASCII maths" and "Standard text"; none of the "Output: ..." categories seem to apply. The line containing the output label is colored by "Standard text" and the remainder of the output is colored by "ASCII maths".

I guess "ASCII maths" is OK, but it seems like the output label line (aside from the output label itself) should also be colored according to "ASCII maths", not "Standard text".

Also, when set_display('ascii) is in effect, font size for output is governed by the font size of "Math Default", but the color is governed by the colors for "ASCII maths" and "Standard Text" as described above.