TL;DR
Transport belts in the inventory fall short of representing the idea of a transport belt in the world. They shouldn't!What ?
Here's the old (0.17) icon for belts, which looks similar to belts in-game (even if not exactly, the color is kept aligned):Here's the new (0.18.27) icon for belts, which is noticeably redder for some reason.
This is especially odd considering that a lot of icon textures very closely resemble their in-world textures:
Sure, like the 0.17 belt icon, they are slightly lighter than the in-world texture, but they are not a different shade of color.
I came up with a "high-resolution" fix texture that I'm satisfied with by taking the in-world texture, cutting out excess, brightening the colors, and scaling it. I would also accept a lighter 0.17-esque texture.
Edit: bonus comparison image with the above texture in-game:
Why ?
I think this improves Factorio by increasing the ease of recognizing the transport belt icon, especially when zoomed out and looking for it on a belt line in your factory. When I think of a transport belt, I think "grey/black and yellow", not "red and yellow" which is what emerges from the smaller versions of the icon.Note: this post has been refined from viewtopic.php?f=23&t=85325