There's no such thing like "Siberian person" - Siberia is huge, really huge and was populated by very different people with different history, culture and genetic heritage.
That said, there never was a single term universally used. Well, there's a word "полукровка" but it was used in context of any racial or ethnic mix-up. Also keep in mind that it's de-facto shifting to being offensive.
But Russia does not have any special diversified terminology like самбо
, метисы
, креолы
, мулаты
which can be used for multi-ethnic people of some Russian origin.
The other thing is that quite often Russian settlers mixed with local people - and new ethnic groups came to existence. In Transbaikal region there were so-called гураны
, in Yakutia there were so-called якутяне
(nowadays this term is used to designated the population of Yakutia as a whole). In modern times, a person who have one Yakut parent and one Russian parent is called сахаляр
. There were so-called албазинцы
, who ethnically were more Chinese, but culturally — a mix between the Russian and Chinese cultures. There were камчадалы
, there were чалдоны
, actually this list can be amended with dozens of other words of this kind.
But almost all thisof these words are purely of historical interest and were more about culture, rather than race.