Some color variations are hard to impossible to sex visually. In the second photo I think I see rusty red by the tail/vent-if so it's probably a male. The throat and face stripe of the 1st photo would also make me think male. However, your best chance of knowing 100% is by their crow. Button males start crowing at just a few weeks of age and never seem to stop for long; if you see them raise their head high and make a weird crowing sound it is a male. If you're unsure what the crow sounds like I'm sure you'll find it online (YouTube).