An OLM who is also a Club TD asks:
Alex Relyea
Here’s a good teaching exercise using pairing cards and hand pairing (for those who remember what those are!)
Have that TD simulate the effect upon the next round of ‘higher ranked player gets due color’ vs ‘random due color’ or whatever other rules you care to use. (I suggest you try it yourself first several times.)
My favorite teaching exercise when training TDs was one that actually happened to me in a real event. Take an event with at least 16 players. Black wins every game in round 1 and round 2. Now, pair round 3. For a bonus, pair round 4. (Use two or three different scenarios for who wins in round 3.)
It only goes to the higher-ranked player if both players a equally due the same color and both players have the same color history. The higher score is higher ranked, and if they have the same score then it is the higher rated that is higher ranked.
As far as being an advantage goes, it is “due color” not a specific color, and the due color may or may not be an advantage (such as the final round with both equally due for black).
The idea of “higher-ranked gets due color” (which is only the last rule in a list of about five rules, and kicks in only if none of the first four rules decide the issue) is a good one because it tends to reduce color problems in future rounds in the upper score groups.
It can be argued (in fact, I think it’s a listed variation) that, in the lowest score groups (such as the 0-point group) it would be better to give the lower-ranked due color. This tends to reduce future color problems in the smallest score groups (those at the very top and very bottom), which are likely the hardest to pair.
Bill Smythe
I always figured that this was because the higher-ranked player (which of course is the player with the higher score, with rating used as a tiebreaker) is more likely to be relevant to the final result of the tournament (by getting a prize, say), so it is more important for his/her situation to be as “fair” as possible.
What we used to do when both players had equal number of colors like WBWB vs WBWB or even BWBB vs BWBB (both players were the only ones left with a clean 4-0 score) was to have the players in that pairing do a coin toss for color in the last round rather than use the “higher ranked gets due color.” Nobody complained as that seemed fair to both players.
That is simply using the option in rule 29E4c. It is fine as long as it is done for all such final round games with both players equally due the same color.
You used the incorrect phrase “equal number of colors” but your examples correctly showed that it is only applicable when the color history is identical for both players.
Tossing for color in the last round (when both players have the same color history) is OK but not really necessary. In effect, there was a coin flip at the start of the first round to decide colors on board 1, and this coin flip essentially remains in effect throughout the tournament.
Bill Smythe
I prefer to flip a random passerby, and let the top rated player call “heads” or “tails” in terms of which body part hits the ground first. 
Don’t forget the other options that are available. I am specifically thinking of what I think of as the top & bottom option. After the first round any color conflicts in the 1 point group gives the higher rated player the due color; any color conflict in the 0 point group gives the lower rated player the due color. As I recall the purpose of using this system was to try to minimize future color conflicts. The assumption under this system is that in the vast majority of the cases the higher rated player will win. I am promoting this system, I just thought it needed to be mentioned. This probably would not apply to a final round of a tournament.
Larry S. Cohen