Re: thumbnail question
Good group thumbs are Ventramaculata (vents), Amazonica, Lamasi/Sirensis, Variabilis, Summersi, and Vanzolini. Fantastica can be grouped but I believe it's a little more important to have equal numbers of sexs. Most of the others the sex ratio and even or odd numbers is not crucial.
I think that the blue and orange you are thinking of is Varadero Imitator. Is this what you are referring to? Imitators do best in pairs, as in one pair per viv. Imitators are a wonderful first thumbnail.
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