This jpeg came out much darker than the colors I was seeing in Krita. Now the likely culprit as to why my colors are off is probably because I haven't calibrated my monitor yet. But if the monitor calibration is at fault, why did i see lighter blacks in Krita than the saved image? I would think the jpeg would have came out looking like the one I saw in Krita and I wouldn't have noticed my colors are off until I see the same artwork in another monitor. Just curious... also, how would one calibrate a monitor in linux mint serena if one doesn't have a colorimeter? Do I have to depend on the online monitor calibration sites?

It's because you worked in 16bit which has by default a linear space for better color mixes, but you didn't prepare your image for the web by converting the image to an sRGB space, and you probably saved as a 16bit png as well, which makes social media sad, because that's super-big .

The official docs have explanations on what needs to be done.
https://docs.krita.org/Gamma_and_Linear
https://docs.krita.org/Saving_for_the_Web

@therahedwig

I checked the properties of the file and it says I was on an 8 bit color space with the indicated icc profile you mentioned. I open the file and the blacks still look better than in the jpg.

I actually found info at the old krita manual that helped me figure out why what I was seeing was off.
https://userbase.kde.org/Krita/Manual/ColorManagement

At the end of that document, the page suggested to not use the system monitor profile and instead use one of the sRGB elle profiles. I went and unchecked the box to use the system monitor profile and lo and behold, my image matched what I see in the web.

Do I still need to calibrate my monitor if Krita's icc profile does a good estimation of colors?

Ah. The problem here then is that your webbrowser cannot show images color managed, using your color profile you made. This means that all the images on the internet you see are incorrectly displayed, and not the ones in Krita.

The default profile can sometimes be bugged, so hence we suggest using srgb, but if you made one yourself, then the problem lies with your webbrowser. Not using your monitor profile then means you might have no trouble with images for the web, but you will have trouble with matching up images for print. This is the tradeoff you make.

thanks therahedwig. I'll stick to the default sRGB elle V2 icc profile.

Wow, I have a bad habit at posting in the wrong forum. Please move this post accordingly. Thanks admins.