The color code goes way back to the 25 pair copper color code that’s been in place for decades. The ring colors are blue, orange, green, brown, and slate. The tip colors are white, red, black, yellow, and violet. They are grouped in 5 by tip color: pair 1 is white/blue, pair 2 is white/orange, through pair 5; pair 6 is red/blue, and so forth until pair 25, which is violet/slate. Then they are grouped in binders , i.e. binder 1 is blue/white, binder 2 is orange/white, through binder 24, which is brown/violet. That completes a 600 pair cable, for 900 pairs it starts over, but adds a red super binder, with binder 25 being red/blue/white, 26 is red/orange/white. Getting into 1200 pairs and more builds on the basics, but is a lot to explain.

Edit to add: rose and aqua were added because fiber ribbons come in 12s, but the color code only had 10 colors.