This is more a problem of the way most digital cameras work out the exposure, that a colour correction issue. When you have two strong colours in a scene, then the camera tends to overexpose the most prominent channel to bring up the other channels. The answer is to look at the histgram after taking the picture, with it seet to three channels rather than simple luminance. ISTR reading that the Canon 1DX is the first DSLR which works out exposure based on each channel seperately, but I just tried to Google that without success.
Anyway, to answer your question, your rose is completely blown and unsavable. You could certainly improve it, but it will never be a good picture.
"Any way to get the color correct on roses?"
Of course: with a properly exposed photograph.
The red channel in your Canon 50D shot is totally blown. I agree with Trevor, this image is totally beyond salvation.
When faced with some examples. I'm often tempted to mention the "Talent" plug-in. Your 'Shoot it again' filter would do nicely in this case, however.
Raw or JPEG? What colour space are you using?
I find that flowers really push the limits of smaller gamuts, and a bit of extra processing is needed to accomodate them.
Firstly, Raw gives you more chance of recovering the deep reds. If you shoot JPEG, then you should choose AdobeRGB as your colour space, and err on the side of underexposure.
Secondly, converting these images for display on the internet and budget printers usually means rendering reds out of gamut, and you'll see 'blockiness' as subtle tone and hue shifts are lost in gamut conversion. To get around this, you need to experiment with Red saturation and luminance changes, as well as using the proofing tools. I do all this in Raw before I even get to Photoshop, but some people prefer to convert in ProPhotoRGB and use Photoshop's HSL filters to control gamut.
This image was shot in Raw, and adjusted in AdobeRGB workspace to produce minimal clipping (the bright reflection on the top of the right flower).
The first image was converted from AdobeRGB to sRGB using Relative Colormetric intent.
The second image was obtained by going back to Raw, changing workspace to sRGB and adjusting red luminance and highlight recovery.
Yamma, your tulips are still over exposed. This was shot in RAW, but it would have looked exactly the same as a JPG. In actual fact I used a Lumiquest 3 on a 580EX2 on a curly e-TTL extension cord (the cheap Chinese knock off because it is longer, and _much_ cheaper than the Canon version). I call this my secret weapon for shooting close ups, because it gets the exposure right every time; lets me under expose the ambient a wee bit to delineate the foreground from the background, and allows me to shoot hand held on the fly at f16.
Yamma, your tulips are still over exposed. This was shot in RAW, but it would have looked exactly the same as a JPG.
Agreed it would look the same, because you underexposed yours.
Negative Exposure settings in Camera Raw can often recover blown reds.