Not sure that its a right way but you can try:
1) Extends from KONtx.control.PageIndicator
CODE
MyCoolPageIndicator = new KONtx.Class({
ClassName: 'CoolPageIndicator',
Extends: KONtx.control.PageIndicator
});
2) Declare your font style
CODE
Theme.storage.add('CoolPageIndicatorTextLink', {
styles: {
'1920x1080': {
normal: {
color: 'red'
}
},
'960x540': {
normal: {
color: 'red'
}
}
}[ Theme.keys.screen ]
});
3) Add alias to general PageIndicator style
CODE
Theme.storage.alias('CoolPageIndicator', 'ControlPageIndicator');