matching color from a photo

The colour is changing because the photo is most likely RGB and you said you're converting to CMYK when you use the eye dropper to grab the colour.

If you want the colour to match, you need to use the colour picker (eye dropper) in the same colour mode as the photo (RGB), and using the same ICC profile (probably sRGB, Adobe RGB, or uncalibrated). One easy way to start a document with the correct settings is to simply File > Open and select the photo. Illustrator will embed the photo in a new document with the correct colour mode and profile. Then you can use your colour picker to reliably get the same colour.

One additional step you may need to do is ensure that your RIP is applying the same render intents to vector and raster colours. I'm not sure where that would be in Flexi, but it's a question that comes up here all the time, so try searching for it.

 

The other issue, once you start sampling the color in RGB, will be that the color in the photo is not one uniform color but a blend of lots of colors that are close. They'll vary because of lighting over the object's contours. So if you sample one pixel you'll get one color, while the neighboring pixel will be another.

 

if the printed color is ok for you, I would compared that printed image to a pantone chart and use that pms color.

 

I would say that the colour is actually made up of thousands of colours..grabbing one pixel won't work. I thought the same thing way back when my printer weas new and I never could get a bright rich red, and then I printed a photo and the colour was perfect...on closer examination you see that it is made up ofthousands of blending shades of red

 

Also when using the eyedropper make sure you set it to sample a 3x3 or 5x5 average in the options if the color is dithered as mentioned above

 

I wish there was a tool that took a sample of a an area of pixels instead of just one pixel for this reason. It still wouldn't be perfect but taking multiple samples and averaging them would seem to work better.

Edit: Looks like I missed vector doctor's comment. I learned something new today!

 

It probably has more to do with the color management of your rip than the sampled values. I'm not familiar with Flexi, but I've run into this before. For example, I placed a photoshop image into illustrator, sampled it and created a spot color "xxBlue" using the same exact values. My rip didn't recognize the color name so it allowed me to enter the values manually. The two items printed very different. GMG explained that the manual values aren't color managed, that you're bypassing color management handling it this way. So in order to get them to match you could either add the spot color to your color library, set your spot color to process in the illustrator swatch, or just make sure that both printed items are sent through on the same print queue.