Hello,
I have been involved with a community that supports cl0wnt0wn. He is a Twitch partner who streams Factorio five nights a week and hosts a subscribers-only server.
Twice, the community has opted to include your mod, but the one drawback for them has been the iconography that you use for the fuel. I had some time today and I decided to play with Photoshop Elements to adjust the colouration of the regular rocket-fuel.png. We figured that we would keep the colours consistent with the three tiers of belts in the vanilla game. So tier 1 is yellow, tier 2 is red, and tier 3 is blue.
I have posted a sample image in cl0wnt0wn's Discord #factorio-general channel, so that his community can evaluate my work.
Would you be interested to have the .png files that I created? I have not verified how well my selections match the "main" colour of each tier of belt, but by my eye they seem to be in agreement. Since I saved a .psd file, I can make further refinements and create better versions if necessary.
Please let me know. cl0wnt0wn would like you to put these files into your mod, so that an update to roll the mods will effect the replacement automatically.
Thank you for your time.
mirigu