Helping people with computers... one answer at a time.
Color matching from device to device is difficult. Most monitors are not well calibrated initially, but doing so can return excellent results.
I enter textile art into exhibitions. The first phase is with jpegs. I have a PC and most of the galleries use Macs. When I tried on my PC to make the jpeg image exactly match the colors in the original I was really surprised how different this looked on a Mac it was way too saturated and really I would have been better to leave the image alone. How do I set up my monitor to look the same as a Mac without buying a Mac? Can i set my desired gamma to 1.8 as Macs are, will this help or just ruin my own monitors rendition. Is this gamma setting the difference or are there other reasons.
First, let me say that I don't believe that this is a Mac versus PC thing at all.
I have two identical LCD monitors on my system, and even when I drag a picture from one to the other, or better yet split it across both, I can see color differences between the two.
The bottom line: color matching is really, really hard.
I will say this about your gallery's Macs: they've probably invested in higher quality monitors, and perhaps even taken the time to calibrate them.
And calibration is the key.
As I said, my two otherwise identical monitors display colors that are slightly, but visibly, different. In my case, for the most part, that's not a big deal. The things I deal with rarely need that level of color accuracy anyway. And as I sit here I'd be hard pressed to tell you which one is "wrong". My guess is that they both are, to some degree.
The solution, were I to need it, would be to calibrate the monitors. This is typically more than just gamma, it often involves several settings that are often monitor and video card driver specific.
And I'll readily admit that, for the most part, the specifics are well beyond me.
There are actually several problems in getting things "right".
One is to define "what's right?". I could get my monitors to match each other, perhaps, by fiddling with all the controls and color settings, but how do I know that those colors are indeed accurate? Just like you, if I take a picture to someone else's computer, how do I know that the colors will show up the same there?
There are, in fact, devices that will let you calibrate your monitor to a somewhat objective standard. You place these devices in front of your monitor where they examine your display and provide calibration settings for it. I've not tried these, but my understanding is this type of adjustment is typically required for true machine-to-machine color portability.
The larger problem on the web is that it may not really matter just how wonderfully calibrated your machine is ... the machines of your website visitors or photo viewers may not be calibrated at all. As such, what they see may still be wrong, and that's quite out of your control.
If this is something you do often, I'm thinking that the thing to do would be to use one of the calibration devices I mentioned above. If not, many displays and video cards offer manual calibration tools and steps as well, but the specifics will vary based on your manufacturer. While the Mac apparently includes color calibration tools, most PCs do not. A quick Google search on "monitor calibration", however, turns up many sites with more detailed information and tool recommendations.