How can I identify color if I have only LAB coordinates? Is it possible to do it by using x rite spectrophotometer?
Yes... and no.
You have already a color... a Lab color.
Imagine you want to identify a speed, in terms of some scientific value, like a fraction of the speed of light. 1/1,000,000 e. You do have a speed.
Now you need to convert it into something a starship can handle. Probably it can, and that speed is let us say 90% of the speed of the spaceship.
But if you want to translate that into a horse running. It can not.
That is what out of gamut means.
Depending of what color is it, and what color profile you are using, you can translate that into that system... 90% of cyan? 60%? or out of gamut.
Some systems recompress and reinterprets the values.
"Oh. I can not reproduce all the colors, but I will try to do my best and, because I can not run at that speed, but the spaceship used its 90% speed, Me as a horse I will also run at my 90% capability and we will all be happy"
So there you have it... 90% horse speed... I mean color, so you have a dull color, not the original.
So yes, and no.
Based on your coment:
LAB coordinates and then I can match a color.
Match with what? A Pantone? A print for a magazine? Car paint? a Plastic? Cloth?
Xrite now owns Pantone, so there is a chance you need to match the data with a specific type of Pantone chip.
The simplest way to convert would be using Photoshops colour picker or Kuler
Entering in the LAB values these tools will automatically spit out the HEX/RGB/CMYK values.
Sorry not sure what you mean by identify.
I am attempting to do the very same thing, convert lab values of an absolute neutral gray 38,0,0 into a Sherman Williams paint.
I think for me the easiest solution is to print out a 5"x5" color swatch using Gracol color space on a Oris calibrated Epson 9000. Take it to Sherman Williams have them read it with their X-Rite device and call it a day. I will speak to the paint rep to see if he can input lab values, HEX, RGB, or anything else I can give him from a Photoshop calculation.