Hey,
The Bangka's represented thus far, in the U.S., have been markedly brighter and redder than some of the Sumatran Red Bloods, imported or bred here in the U.S.
However, that is not to say that you can't or won't be able to get your hands on a great Sumatran Blood, with great color that will morph into one outstanding Red animal. That really all depends on the lineage (sire/dam), if that is known, but even that won't gaurantee you the reddest animal, as there is so much variation.
I guess that the only way to ensure that you get your self an animal with the potential for great color, is to get your self an animal that is at least a year old, whose colors are starting to show truer to what his/her, adult colors might look like.
Hope that makes sense! 
-Angel
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"Until we lose our self, there is no way of finding our self."
-Henry Miller.