The languages do have default colors, so that Dwarvish if gold without you having to explicitly set the color to gold. That way, if we wanted to change colors sitewide without editing old posts, it would be easy. You can still change color within the language, so you could, for example, start off with Orcish text and then select one word and make it blue.
Each language can have its own default color, font, size (and the languages [i:y1nfqb5t]do have[/i:y1nfqb5t] different sizes set, to keep the characters’ height consistent), background (highlight) color, text direction (left-to-right vs. right-to-left), overline/underline/strikethrough, letter/word spacing, and text drop shadow/stroke. There aren’t toolbar buttons for most of those effects, though, but they’re possible to set on a per-language basis.