It's worth a try, if you print darks (pretreated) and the colors are fine with them then yes I would try it, but bear in mind that the pretreatment for light fabric is different.
We find that some artwork requires pretreatment on white shirts to get the color saturation we want, that said today I'm printing an order of 46 white shirts and the artwork looks fine without any pretreatment.
Hope this helps.