All above are all regular Rainbo's, once you have an inky in hand you'll never forget it. Generally the muddier the better as far as desirability goes. Here's one from feebay w/ a backlit shot showing the "muddy" base. As Ric said color can vary quite a bit between light and dark, a link showing some dark and light based inkys.
LINK :: https://www.allaboutmarbles.com/viewtopic.php?f=7&t=38107&p=281983&hilit=peltier+inkys#p281983