Keysight is Yellow, Green, Blue, Red, Cyan, Magenta, Purple Orange
Tek is Yellow, Cyan, Red, Green, Orange, Blue, Magenta, Teal
I don't think any other major brands, even Chinese ones, are making 8-channel scopes right now. It's easy enough to find pictures of these scopes online. There doesn't seem to be a standard, sadly.
Oh Yokogawa apparently has one, it is Yellow, Green, Magenta, Cyan, Red, Orange, Blue, Purple. Different again!