Dear Matt: There are no-colored cartridges, but certainly the Ruby 2 is one of the less colored and neutral/natural cartridges and a very good tracker too. Maybe the people that say is " too colored " have " coloration problems " some where in their audio links that can't match with the 2.
There are many cartridges out there that can match your priorities: I mentioned the Ruby 2 because is a very good cartridge and because it is on your list, but the Sumiko Celebration is a very good choice too or the Shelther 90X or Van denHul Frog or Condor. No, the Koetsu is really too colored and with an unbalanced frecuency response.
Now, you ask for the LP, then I can understand that the LP is on your budget, if this is true go for it or for the Dynavector XV-1. You can't go wrong with either.
Regards and enjoy the music.
Raul.