Splitting services across staff columns is easy. When you're creating the booking, just click once in the column of the stylist who will be doing the first service (eg the colour) and then click "Make Appointment".
Search for your client using their name or phone number and select the client you want. Then click on a category and select their first service:
Then click "Add service" to select the next one. Additional services will automatically go into the first stylist's column, but don't worry, you can move them to another column super easily!
You can do move a service to another stylist's column while you are creating the booking, or afterwards. Just click or tap on the service you want to move, hold, and drag it to the column of the staff member you want: