Wikipedia says that this is a Cayley table of Dih4:
Can somebody explain what are these numbers/colors mean?
Wikipedia page on Cayley table uses letters and does not mention any numbers.
Also what are these small tables with red squares on top/left mean?
There are other examples of such a schemes like here
Update:
I recently figured out that 'small tables with red squares' are actually a permutation matrices corresponding to the group's elements, but the question about numbers and colors is still open.
Update 2:
as Nex pointed out the numbers come from Caley table of S4 group. Symmetric group S4 page contains explanation of the colors:
Even permutations are white:
- the identity
- eight 3-cycles
- three double-transpositions (in bold typeface)
Odd permutations are colored: - six transpositions (green)
- six 4-cycles (orange)