Title basically. Make a Mk3 (probably happens with the other ones too, but I didn't test). Pick it up, and put it back down. The color reverts to the original color even tho the inventory (and tooltip) shows the right color before placing it down

oh, 2 days ago, sorry for late response.
Also sorry about the color i kinda cheap out when i added the script for colors (i'm still a noob at coding). As in whenever you place a spidertron-extended spider it will be the default colours. I should be able to script it to save the color when you pick it up and when you place it again to have the color it previously had, just need to check in the factorio api how to do that, or check if there is another way in the api.
Thanks for the info, will work on it.

Looks like it still defaults to the original color when picked up and placed.

I don't know about the api or scripting but maybe you can get ideas from Klonan's Companion Drones. When he picks his up his drone and and places back down it shows and keeps the correct color. Just a suggestion.

Thanks for the info, will try and look over it when i get the time (barely had any time lately, insert ~sad_cat~)

I think that the base game does the saving of spidertron colours automatically for you. You just need to check when placing a spidertron if its color is the default or not. If it is the default, then color it. If not, then don't.

Thank you Xorimuth, i did the change as suggested, in 0.3.7 the spidertron colours can be changed and will keep the selected colors after being picked up and put down (as long as it's not the base color). Tell me if anyone has any issues or other compatibility problems (i haven't fully tested with everything). Oh yeah and the cannons on the immolator and ghost weaver cannot change colors, i would need to give Resar flours or sweets to convince him to draw the color overlays for them or how they are called.