After more testing I noticed that it will work if the font is installed on the client computer BUT only if the font is specified in the field inspector.
It won't work with a calculation field like
TextSize( TextFont( TextColor( character; Color ); "mycustomfont" ) ; fontsize)
So I lose all the flexibility. I could live with the font size but I really need the color in the calculation.
Regarding rich text
From the webdirect 14 guide
Other features, like rich text, simply don’t work.
From the webdirect 15 guide
Other features, like rich text, work in limited circumstances or don’t work at all
So what has changed exactly ?
Will textcolor(mytext, mycolor) work on webdirect 15 ?
Well, I tried Texcolor with a Webdirect 15 trial and it does not work.
FileMaker WebDirect offers limited text styles. Highlighting, paragraph text styles, and tab stops are not supported. Rich text is supported only when applied to fields, buttons, and layout text. FileMaker WebDirect only supports rich text that is supported by the web browser.
It looks there is no way to set font size or color of field value on WebD, so calculated or preset values also not support the styles partially applied.