MyHeritage has added labels (colored dots) and favorites (stars) to the DNA matches lists. These are extremely similar to the ones at AncestryDNA. One advantage at MyHeritage is that when you select multiple colored dots to display, you are shown all the matches marked with either one, whereas Ancestry only shows the matches who have both. Another advantage is that MyHeritage gives you 30 colors as opposed to the 24 at Ancestry.
The downside of the MyHeritage implementation is that you can only see and edit these colored labels on the DNA match lists, not on the actual match page or its in common with list. According to the blog post that My Heritage wrote on how to use this feature (click here), those pages will have the labels in the future. Also when you export your match list from MyHeritage there is no indication of those labels in the resulting CSV.
So how might you use this new feature? First of all, for myself, I use the favorites star for matches I want to come back to later. However when working on an unknown parentage case, I use the star for just the paternal side which is helpful for various automated tools.
If you have already assigned colored dots on Ancestry, my advice is to use the same colors on your MyHeritage labels for the same groups. Personally I have assigned a color to each great-grandparent line, except my Bavarian line which has very few testers and no matches that I can confirm other than the one 2nd cousin that I convinced to test.
Then I have a few fifth grandparents who seem to have many tested descendants that match us, so they get colors too. Next I assigned colors for as yet undetermined matches from the same localities that my ancestors are from, those include labels for Norway unknown, Germany unknown, and Ashkenazi unknown. Click here for my discussion of how I use the very similar the Ancestry labels.
If you have gone through your MyHeritage matches and left yourself notes as to how you are related then assigning labels will be easy. Another approach is to use the filter for “Has a Theory of Family Relativity” to find the matches where MyHeritage has a theory about the relationship.- I did a presentation on FaceBook for how to use those (click here) but never wrote a blog post about it. The updated image of a slide from that presentation, shown below, explains how to get a list of just matches with a theory.
Also Roberta Estes has a nice blog post on how you might use these colored labels at