Once you have your colors imported, printed and measured in multiple documents there is the moment to search for the most similar measured color corresponding to color reference. You can find it from Utilities | Find Similar Color / Find All Similar Colors.
This option will search for similar colors for the color selected in the actual document. In this search we have a limit of deltaE. It will not give a valid similar color if the deltaE is bigger than the maximum deltaE selected in Preferences. If the color have other measurements with better deltaE, it will not give a similar color if the deltaE is bigger than the deltaE of the original color/measurement.
Step-by-Step
1. One document having colors imported/created that uses a printer profile.
2. Looking for the similar colors printed, that are created by variations, color world or any color library using same printer profile in two another documents
3. Select a color and with Utilities | Find Similar Color search for colors in all open documents. It will search only similar colors from colors that have measurements and same profile. Colors without measurements will be skipped. If the document of the original colors don't have profile selected, then it will search for similar colors in all documents without profile.
4. When the similar color measurement is found, the reference will appear under the name. The words 'Reference Color' with the name of the similar color, the order and index of the measurement of this similar color. Inside parenthesis "()" will appear the name of the document. For example: Reference Color: #001 0005 - 001 (TFX Library)
5. The similar color (measurement) will be in the measurements table of the original color and the index will be correlative, not the index of the similar color. This index it will appear in bold indicating that this measurement comes from a reference color.