Wait till you get to Sterenko and a little later Adams. Both step up the game so much...
Which ToS did you first get hit by the better art quality?
It was ToS #81
The inker is actually not the person who does the color. The penciler first draws a panel in pencil with the degree of detail ranging from very basic to a complete panel. The inker then goes over the pencils in black ink adding detail if needed. So for example, a penciller might draw spider-man with no webs on his costume and then the inker will ink over the image and add the webs. Coloring at the time was actually handled by the publisher rather than the creative team. In early Marvel, publishing was handled by various third party companies (fun fact: for a while it was actually DC's publishing house that they used) so there was no way for Marvel to credit the colorist(s). Once Marvel created their own publishing house, credits for colorists start showing up in the comics.
Well in that case I'm not sure if I've properly credited everyone responsible, but whoever it was, kudos to them, first time in the order I've noticed the artwork being outstanding.