More unsolicited non-playtester feedback from Spiff:
The purpose of an icon is to represent a concept in a way that allows for quick identification of its meaning. I think the Weapons and Defense icons meet that criteria pretty well (though the blue is perhaps a bit too dark, given that the scales (?) on the icon have so much black on them). And I think it's good that the Energy icon is a different shape than the others. But I think the Energy icon's purple color is too similar to the red and blue, which could hamper its quick identifiability from across the table. With green or teal or yellow or some other color that's visually more distinct from the red and blue than the purple is (purple is just red + blue afterall), you'd be able to tell at a glance if an icon is for Energy, rather than having to take a beat to make sure it's not blue.
My point is that you wouldn't want a third icon's color to be a mix of the other two, you'd want it to be as different from the other two as possible.
I hadn't thought of it before now, but I agree with the energy icon. Just in a different way. The shape is what throws me. At a glance, it's actually hard to distinguish between the Energy and Defense icons. Unless I'm just having difficulty because of the print on my playtesting copy.
I think purple was chosen because it is blue and purple mixed together. Also its shape is a superimposition of the two icons. While it may be difficult for some to differentiate (though I’ve never had a problem myself, even in black and white), I think that may have been the reasoning. If is confusing to enough people, I agree it should then be changed.
I figured that's the reason for it, which is why I wanted to point out that that's the opposite thinking from what you'd need for really good icon design. An icon that looks kind of like two other icons is laying down on the job, icon-wise. ;) It needs to stand on its own.
I'm inclined to agree. It's easy to tell the difference after some scrutiny, but making it pop more would probably be a better choice. Either a change in shape or color would probably do the trick.
I can see the logic in making the energy icon be a combination of the defense and weapon icons since weapons and defense make up the energy of your ship. However, I do agree that when doing this confusion could be avoided by making sure each of the icons and their combination create very distinct shapes and that the colors also reflect more contrast than what is currently shown.