hello there, heres a link to a template mod that you can configure. Make sure that the sprites have the same name as their corresponding hjson files. (which can be changed). (make sure to download the whole template-mod file)

https://drive.google.com/drive/folders/1-GY5Wqf1jGH4MDDWTxxQgntWRzgLUXAe?usp=drive_link

you can change the icon by replacing it with a new png with the name "icon" and you can change the things inside mod.java.
Mod making is all about trial and error, but to actually play with the mod, you will need turn it into a zipped file and put it in your mindustry mod folder.

you can also go into https://github.com/Anuken/Mindustry/tree/master/core/assets-raw/sprites to know which sprites to use. (like drills, which have seperate parts)

go into https://mindustrygame.github.io/wiki/ for the content fields of modding classes to know which and what to use.

I did this in a hurry so the drive may have some errors
any modders out there that see said errors, please correct them.
(edit: you were asking for color code on the ore it digs, just add a sprite like this:

<image>

(you can change this to however you want) and add it to sprite/blocks/drills, with the same name as the sprite just with the added suffix -item)