well theirs is two ways on how to use ::yell colors
1. <c><col=#>
2. <c><shad=#> when you type this ingame you won't be able to see it

example: http://prntscr.com/2zfbw

COLOR LIST:

Blue: 255
Purple: 20451204
Green: 255125000
Black: 330000 <---- these one im pretty sure to use with <col=99999999> type here
Orange: 616582400
Yellow: 200000000 i just tested and if u use it with <shad=99999999> it will show
Red: 800000000 different and Better Colors just try both of them ;p
White: 99999999
shade blue: 22002
light blue : 808080
lime green: 652323 <-------------- this one is my favourite lime green ;p
cyan: 621717
teal: 515214
Light shaded green: 77777777
Dark Blue: 3635

for you Kobar: