difference-

Split-Complementary color scheme is a variation of the complementary color scheme that uses 2 colors adjacent to it's complement. Triadic color scheme use colors that are evenly spaced around the color wheel. Tetradic color scheme uses 4 colors arranged into 2 complementary pairs

similarities

Split complements use a color and the two adjacent tertiary colors of its complement. Triadic color schemes use three evenly spaced colors on the color wheel. ... Complementary colors are opposite to each other on the color wheel, so they create a strong contrast

hope it helps kung di kayo maniniwala ok lang pero sana makatulong❤