Here are a before and after examples of using photoshop to enhance artwork
How far off is the raw scan from the original? Chances are the white background in the raw scan is much more blue- gray than your original art. Also, I would have to guess that your color contrast and color intensity suffered some in the scan.
As you know, making a Photoshop over-all correction of the blue cast on the background will clean up the yellows some at the same time. Without inspecting the original art, it looks like you have done a nice job correcting the scan with possibly some enhancement (or clean-up) of color. I don't believe this is going too far for most uses of the image.
If the corrected image was to be entered for acceptance in a juried exhibition, you would have to be sure that the corrected image is a reasonable match to the original art.
you are right about the scan being poor its actually a digital photograph hence the grey blue background.
nearly all of the original scan has been painted over using photoshop with most of the red dots being totally redrawn so as to effectively clean up the background
You did a real good job—especially working from a digital photo. You must have a good working knowledge of Photoshop. In the future, I think it would better to have the work scanned professionally from the original art. Have it scanned at full size and at 300 ppi. Most fine art printers will tell you they don't need that much resolution. I think it is good for many reasons including any Photoshop work you have to do. With 300 ppi you have all the resolution you need to print it full size on any printing device.
Most professional scanning is done at predetermined settings. Sometimes a large white background area can throw the scanning off some. Not long ago I had a watercolor painting with a large white background area.The results were similar to the background white in your digital photo. However, it wasn't that difficult to correct because the basic color balance was good.
Thanks for the advice If I decide to sell prints of my work I will be sure to do exactly as you suggest.
At the moment I have only been experimenting with digitising and printing using the basic tools I have at my disposal. I have a cheap digital camera, an old version of photoshop 7, a basic canon a3 printer, budget inks and canvass paper and have just about managed to produce some fairly reasonable prints. Who knows what might be possible if I could afford better.