[Admins]

You can create new profiles. If you want to base it on an existing profile and only modify a few values, you could e.g. do
new GuiTextProfile("MyBigTextProfile") {
fontsize = 30;
}

and in the gui object then do
profile = MyBigTextProfile;

From the docu you can get the attributes of a profile:
GuiControlProfile:
autosizeheight - boolean
autosizewidth - boolean
bitmap - string
border - integer
bordercolor - string
bordercolorhl - string
bordercolorna - string
borderthickness - integer
cankeyfocus - boolean
cursorcolor - string
fillcolor - string
fillcolorhl - string
fillcolorna - string
fontcolor - string
fontcolorhl - string
fontcolorlink - string
fontcolorlinkhl - string
fontcolorna - string
fontcolorsel - string
fontsize - integer
fonttype - string
justify - string
linespacing - integer
modal - boolean
mouseoverselected - boolean
numbersonly - boolean
opaque - boolean
returntab - boolean
soundbuttondown - string
soundbuttonover - string
tab - boolean
textoffset - string
transparency - float

The bitmap defines what look the window, text field, scroll bar etc. gets