HT16K33 Datasheet Query
What the data sheet tells me is that if you try to take typically 30 mA from the pin, the row voltage output will be Vdd - 3 volts. So if Vdd is 5 volts, you will typically see an output voltage of 2 volts. 

If your LED has a volt drop of nominally 2 volts, it will be fed approximately 30 mA. If your LED has a volt drop of 3 volts then it will only take typically 25 mA.

But you also have to take into account what the column volt drop might be - it could be as high as 0.3 volts if dumping 200 mA but, with a proper multiplexing system it is likely to be just a few tens of millivolts. However, this didn't become absolutely clear in the few minutes I was reading it.