Color Coding DNA Matches: Lawrence-Little Ahnentafel Color Schemes, MRCA Pedigree Tables

Summary

A Lawrence-Little MRCA Pedigree Table displays confirmed DNA matches as groups with shared most recent common ancestor couples in a pedigree chart; a Lawrence-Little color scheme conveys genetic and genealogical information with color: the hue of a child is a mix of hues of parents; the intensity of color increases each generation. When a Lawrence-Little color scheme is paired with a chromosome segment map, it is easier to see how unknown match segments may be related to known, charted matches.

[NOTE: Known DNA matches in this article have either given permission for their names to be used, or the names have been changed, obscured, or omitted. I thank my cousin-collaborators for their help in our research.]

See Your Matches in a Way That Makes Sense

In this article, I share a color code scheme for pedigree charts, tables, family trees, and DNA chromosome segment maps. I have found it helpful to use the same colors in my pedigree charts as I use in my DNA segment maps. Samples of pedigree charts, relationship charts, and segment maps are shown below, along with explanations of the information the charts display, and instructions on how you can get and use the color codes used in these images.

There are two aspects of a Lawrence-Little color scheme that are particularly helpful. First, and this will be emphasized later during the presentation of color codes as used in segment maps below, the vividness or luminance of the colors become more intense for older generations; this is especially helpful when viewing segment maps, as discussed later, in the second part of this post.

Second, as seen in Figure 1 just below, there is a relationship between hue used to color a child and the hues of the parents. In fact, the hue used for a child is an equal mix of the hues of the parents. If you remember mixing finger paints as a child, then you recall that when you mixed yellow and blue paints, you created green. Similarly, a Lawrence-Little color scheme (so called in honor of my parents) generates a hue for a child that is an equal mix of the hues of the parents. For example, as seen below, the light orange hue used to color Mont Warden Little (my paternal grandfather), when mixed with the mint green hue used to color Ruby Helen Bower (my paternal grandmother), creates the tidal green hue used to color my father, Joe Stephen Little, Sr. (Serious color theory geeks are welcome to examine the Google Sheets spreadsheet attached below to see how the equal mix of hues is calculated.)

The Google Sheets file linked below also, as the close-up of the same pedigree chart in Figure 2 below illustrates, allows me to visually record where my DNA matches reside in my pedigree chart or family tree. When I have verified though documentary evidence and confirmed through segment triangulation the most recent common ancestor between myself and a DNA match, I plot that DNA match in the cell of our shared MRCA couple. Several examples are shown in Figures 2 and 3 and explained below.

After staring at long lists of DNA matches, I desired an easier way to more quickly understand the relationship between a match and myself. Even after determining our most recent common ancestor (“MRCA”), and even with the simple color assignments allowed by some sites and tools, it was clear to me that color could be used more effectively to convey relationships. The genealogical and genetic information that a Lawrence-Little color scheme elevates is the shared most recent common ancestor between the DNA match and the primary individual in a pedigree chart, family tree, or segment map. A Lawrence-Little color scheme captures, combines, and projects the genealogical information contained in an ahnentafel table, the genetic meaning of a MRCA relationship, and the informative power of an effective color presentation. When referencing a specific person, I denote a shared DNA match, relative, or cousin with a large circle, e.g., “⬤ Rob SHEPHERD (949;11;121)”; the numbers in parentheses following a name contain match information about shared DNA between the pedigree primary and the match, e.g. (949;11;121) means a total of 949 shared cM across 11 segments, with the largest segment being 121 cM. (Thanks to Donna Paul of the Facebook group Genetic Genealogy Tips & Techniques for this suggestion.)

You can see this informative power in Figure 2, an enlarged excerpt of the complete pedigree chart of Figure 1. Each cell in the table holds relatives with shared MRCAs. For example, my paternal grandfather, Mont Warden Little, is the son of Jethro Wilson “Joe” LITTLE and Lou BARE. Together, Joe LITTLE and Lou BARE are the founders of the LITTLE-BARE family group. Descendants of Joe Little and Lou Bare are members of the LITTLE-BARE family group. In the table / pedigree chart shown in Figure 2, the cell holding members of the LITTLE-BARE family group is the lower-left cell colored with light orange, which holds Mont Warden Little. The relatives also held in that cell are NOT his descendants, but rather his nieces, ⬤ B.JOHNSON63, ⬤ D.JOHNSON58, and ⬤ D.SMALL39; this cell would also hold (had they taken DNA tests) Mont’s siblings, nephews, grandnieces, grandnephews, and all their descendants, all of which are descendants of Joe Little and Lou Bare. Going back in time one generation, Joe Little is the son of Ambrose LITTLE and Theodocia WITHERSPOON, founders of the LITTLE-WITHERSPOON family group; the cell holding members of the LITTLE-WITHERSPOON family group includes Jethro Wilson “Joe” Little and his great-grandniece ⬤ S.HAW45 (who is my confirmed DNA match and verified third cousin) and a ⬤ HARE relative and a ⬤ HARR relative. Similarly, going back yet another generation, Joe Little’s mother, Theodocia Witherspoon (my 2nd great-grandmother), is my ancestor in the WITHERSPOON-CURTIS family group, so named for Theodocia’s father Col. William Pettigrew WITHERSPOON and her mother Nancy Curtis; my verified fourth cousin and confirmed DNA match ⬤ D.BOOKMAN65 is placed in this cell holding the WITHERSPOON-CURTIS family group.

The relationship charts in Figure 3 are offered to make clear how the DNA matches discussed above, ⬤ D.JOHNSON58, ⬤ S.HAW45, and ⬤ D.BOOKMAN65, are related to the author through our shared most recent common ancestor couples.

Author and ⬤ D.JOHNSON58 are second cousins, sharing Little-Bare MRCAs.

Author and ⬤ S.HAW45 are third cousins, sharing Little-Witherspoon MRCAs.

Author and ⬤ D.BOOKMAN65 are fourth cousins, sharing Witherspoon-Curtis MRCAs.

As mentioned earlier, a Lawrence-Little ahnentafel-based color scheme is not only useful in pedigree charts, tables, and family trees, but the work done there pays rich dividends when leveraged in DNA chromosome segment maps.

Benefits of Coordinating Colors among Charts, Tables, Trees, and Segment Maps

Recall that there are two distinguishing features of a Lawrence-Little color scheme: 1) vividness or luminance of the colors become more intense for older generations, and 2) the hue used for a child is an equal mix of the hues of the parents. These features quickly lead to benefits when extended and coordinated among pedigree charts, tables, family trees, and chromosome segment maps. First, the relatedness among associated family groups becomes visibly apparent because the hue of a child’s family group is derived from an equal mix of the hues of the parents. This is seen in Figure 4 below. Second, as the vividness of older generations are more intense, these older segments “pop” or “jump out at” the researcher. This is also seen in Figure 4 below. Additional benefits of a Lawrence-Little color scheme will be noted after several segment mapping tools are introduced.

The software that I find most helpful for segment analysis and determination of most recent common ancestors (MRCA) between DNA matches is GDAT (short for “Genealogical DNA Analysis Tool“; see, too, their Facebook Group). Figure 4 below shows a segment map generated with GDAT. Notice that the segments in the map use the same color codes as the pedigree charts in Figures 2 and 3.

As Figure 5 below illustrates, these color codes can also be used in DNA Painter. Here I exported my segment data from GDAT, massaged it a bit to conform to DNA Painter’s import requirements, then uploaded the segment data and color codes into a segment map at DNA Painter. (If interested, please let me know, and I’ll break down those steps in a future post.)

An additional benefit of a Lawrence-Little color scheme is revealed by examining the GDAT map in Figure 4 and DNA Painter map in Figure 5 while keeping in mind that both tools “stack” older DNA segments on top of (or in front of) younger segments; that is, smaller segments from earlier generations are given a visual preference over more recent generations represented by younger family groups. The increased intensity of a more vivid luminance assigned to older generations with a Lawrence-Little color scheme compliments and leverages the visual preference already given them by GDAT and DNA Painter.

Getting and Using the Lawrence-Little Color Scheme

Below is a link to a Google Sheets spreadsheet which contains a sample Lawrence-Little ahnentafel color scheme, the same one used to create the images, charts, tables, trees, and segment maps in this post. The Lawrence-Little chart format and color scheme is released under a Creative Commons license. The file contains several tabs or worksheets: 1) “color codes,” which, as seen in Figure 6 below, contains the color codes in several formats; 2) a sample pedigree chart/table built to hold DNA matches by family groups (as explained above); 3) a “clean” pedigree chart/table; and 4) an “info” tab/worksheet with more information, including the author’s contact information.

Different tools and apps have different ways to select colors. The codes included here will meet almost every app and tool (RGB codes will be added soon). The HEX code is perhaps easiest, if that is an option for you. If your app or tool asks for Hue, Luminance, and Lightness (or Saturation), you can find those here. Apps will likely use one of several scales, from high to low: 0 to 100, 0 to 240, or 0 to 255, or 0 to 360; all those options are included here; you just need to determine what the maximum value your app uses, and use color codes from the corresponding column.

You can get access to the Google Sheet file and get the color codes here: https://bit.ly/Lawrence-Little-color-scheme.

Coming Next:

Soon I will be sharing here a tool that will allow you to select your own starting color from which to generate a Lawrence-Little ahnentafel-based color scheme. In the pedigree chart at the beginning of this post, a light blue hue is used to color the leftmost cell, the primary individual in the pedigree chart. Instead of light blue, the Lawrence-Little Ahnentafel Color Picker coming soon will allow you to select the color of your choice for the primary individual and will generate all the color codes needed for your pedigree charts and segment maps.

Best wishes, Steve.

PS: If you find this useful, have questions or suggestions, or you think we may be cousins, please let me know.

Updates:

I have incorporated the suggestions of several folks into an updated version of the Lawrence-Little Pedigree Table and Color Scheme. Both the new and archived versions are available at the link above. A depiction of the updated table is shown here as Figure 7. Thank you for your kind words and encourage, and please keep the suggestions coming.