What do you guys think of this representation for on/off contacts? C003 is on, then others are off. I have never seen the logic represented in the color of the label instead of the color of the contact. I think it is hard to determine the states, especially when you have many contacts on a rung.
Not sure the contrast is high enough, especially for someone with any form of color blindness. I would put a box behind C003 when on, which relies on no color at all.
Yes, the color difference is an issue also, but I have seen a version with high contrast colors, and it is better, but still not quickly discernible. Their previous generation product did it like you suggested:
Even with changed colors, I don't like the depiction. And no, you can't change the colors. Yes, you would think you should be able to, but not possible by the user.
You are stuck with the imagination and aesthetical sense of the software developer. And PLCNext, which seems to be KW Software, is one of the ugliest IMO.