Is there any difference at all with the different Churchill fin colors? No.
While the short answer is no if your not in a hurry and would like to learn a bit more, I have some more interesting information for you:
There are swim fins that are literally color coated by their characteristics, namely Viper fins and Viper Vectors. Their standard model color is yellow and the orange model is their more flexible and soft model.
The Makapuu and Slasher Churchill fins vary in color but are no different, they all have the same typical characteristics.
Actually, there is a slight difference in the color of a Churchill fin, but it is not meant to be different. The color black is the softest and white is the hardest and stiffest. However, the manufacturer does not mean to confuse any consumers. It is a very subtle difference most most of the time, but the white model is very hard, more so than the black model, this is why you rarely see white fins being sold.
Churchill fins, and most other fins besides Vipers, have many colors. Churchill makes 3 fin boxes the original blue, orange, and one fin box that varies yearly. It changes with popularity. When most surf shops order fins, they have to get 4 boxes at at time, so it is always 3 original colors and the 1 special color.
Here is a quick history of the color combos through the years, starting from oldest to newest.
Back in the day they came out with all green fins, I believe they ran this color for several years:
They ran this very popular yellow and black color combo for years:
Next, they came out with the same blue but a brighter yellow blade, much brighter than the original orange blade. It had mixed reviews. The blade was stiffer because as the colors go brighter on the color spectrum, become stiffer (and as the opposite, black is the softest color). Many Australian bodyboarders called it citrus and didnt like them as much as the original orange color, or gold color as they call it.
Then they released black fins, same as the original (and all the other different colors, just black in color). I actually could not find a picture of the fins (it was around 10 years ago and many of these old fins are hard to find) but the picture below of Hubbs is very similar to Churchills signature fins. This color was well received.
After the black color, the color combinations were released: black and green and grey and blue.
And lastly, they came out with their first signature fin, the Jeff Hubbard HUBB fin. They later came out with a Amaury Lavernhe signature fin named MOZ that is only available in certain countries. Both were well received.