The colors for Blockland are in RRGGBB format and RRGGBBSS format.
You can also use <font:(TYPE):(SIZE)> to change your font and/or size.
Here's a list of all of the fonts:
Arial
Apple Bold
Arial Bold Italic
Arial Bold
Blackadder ITC
Calibri
Comic Sans
Comic Sans MS
Comic Sans
Heveltica
Impact
Jokerman
Kristen ITC
LCD
Lucida Console
Lucida Sans Unicode
Monotype Corsiva
Outlineletters
Outline
Palatino Linotype Bold
Palatino Linotype
Papyrus
pusillanimous individualcat
Size
SoulMission
Symbol
Tahoma
Times New Roman
Trebuchet MS
Unicode
Veranda
Verdana Bold
Webdings
Wingdings