Hello RS Team,
First and foremost, thank you. RS is amazing, I am a huge fan and as a fellow dev - wow. I run a print farm, I love 3D printing and I have used MANY solutions mainly you know which and also some custom stuff and RS is just better. You deserve every penny, so thank you. Also I program Angular and I am a huge fanboy (so what lol).
Anyway --
When using RS to manage multiple printers it becomes tedious to keep track of what material (color) is where. I am not asking for full filament spool management ( I know this may be a future feature and I know how to the current estimate engine works ). What I am suggesting is a GUI enhancement.
In the main GUI (http://192.x.x.x/#!/dashboard) the printers are listed, and it's minimalist and nice, but it's very confusing at a quick glance even with just 3 printers, let alone with 10 or more.
I know you are busy, I know the GUI is probably not priority and I absolutely know that backend code is way more priority but as a real user I think this is very important. One big reason to use RS over other is because it handles multiple printers so well and it's light, I think your biggest market going forward is multi-users and print-farms (personal or for hire) and this is really important. Heck, even for 1-2 printers it can be useful.
What I am suggesting is adding a button next to the "gear" icon (<i class="fa fa-cog"></i>) in the cards for the printers on the dashboard. There is no filament spool icon in FA still (sad) but maybe you could use "<i class="fas fa-palette"></i>"
Anyway add that icon, when you click it a small widget opens with some basic pre-defined colors, and you can click one. Doing so will change the icon color of the icon (example: fas fa-palette) so in the display bar of card for the printer in dashboard you can quickly see what printer has what color. It's purely aesthetic for tracking, but this makes alot of difference for admins of multiple printers, seriously.
There are quite a few components for Angular to make a quick color picker such as "ng g c color-picker" ;) anyway here is a quick mockup - maybe it helps. I know Angular if needed haha ;)
Here is a rough mockup: https://i.ibb.co/c64vr71/concept-RS.png