Forgive my whimsy on this, but I do like a good (and sometimes bad) pun.
In the good/bad old days of film photography no-one ever worried about colour balance (except those unfortunate enough to have to use slide film) because everything was corrected automatically for you by the printer. Now no-one worries about it now because the cameras correct for you automatically too. Sort of.
But only sort of.
So if you're manipulating your images in a digital darkroom, rather than in a physical one, how do you know whether you've got things right? You might think you could just look at the image on screen, and when it looks right then it is right?
There's a whole industry out there, trying to sell you tools of various kinds to calibrate monitors correctly (and yet more guys trying to sell you REALLY NICE photographic quality monitors for quite significant amounts of cash). I am aware that my 2 monitors are quite different: the older Samsung at home having much better resolution of bright tones and a nasty habit of darkening as you move your head around, while the Dell U2414M that I'm looking at is much more neutral.
It's a bit of a problem when it comes to showing other people your pictures. Everyone else's monitors are also a bit different unless calibrated, and that scene with all those exciting but subtle colours may just look dull to them. Alternatively your bright and exciting image may appear garish & crude on their screen. It gets even worse when you get stuff printed, because you want the the prints to look just like they did on screen, and of course they seldom do. And it also begs the question whether your printer (either at home or the shop you went to) is calibrated too.....
When I had those canvases printed a while back they came back *looking* pretty much like what I'd seen on screen, yet the images that I had printed in Bicester for the Somerton picture contest were a fair bit darker & warmer than even this (factory calibrated a couple of years ago) Dell. TBH I was not entirely happy, but also not sure who was at 'fault', if it could be described as a fault.
Chris wanted some small pics reprinting, so I requested a couple of 12X8 prints done from the same files that were used for the Somerton images, but from a different vendor. They came back earlier this week, and a quick comparison in daylight showed one to be virtually indistinguishable from the other, while another one was somewhat lighter and a little more yellow. The smaller prints we had re-done had been adjusted by me through lightroom and viewing on this Dell (I'd had to do resizing too, because they'd been cropped horribly by the software at the original printer) so it wasn't a really fair comparison, but they came back much more neutral and cleaner than the originals.
My conclusion is that one needs to know one's printer (and monitor!) and adjust accordingly. If I start doing professional work, as I hope to eventually, then I'll be investing in calibration tools and keeping a very close eye on printing.