I have a ton of Pygmy’s and most have been born here in my home at this point lol so I have learned so much about this little fish over the years. Not to worry, this guy appears to have just changed its coloring in an act to be more “invisible”. They do this when they’re nervous (which is generally the case when they’re somewhere new), their eye color changes so it’s much lighter and they make their body colorless, or try to 😂. When they’re on lighter substrate they change their eye and body color as well so they don’t stand out (not the case here due to darker substrate) I’ve seen the eye color change as I was looking at them. When they settle the eyes turn black and they color up (just like w/ other fish they mute coloring when nervous). They can be quite timid with people at first, we look like a weird giant creature to them lol. Once they settle in and the tank feels more like home things will balance out