Orange Bourbon ripens to orange rather than red or yellow — a third colour mutation of the same variety.
Is it different in the cup
Marginally, and claims vary. Producers who grow it often describe it as sitting between red and yellow: sweeter than red, more structured than yellow.
Blind evidence for a consistent difference is thin. Growing conditions and processing dominate.
Why it exists
Cherry colour is controlled by a small number of genes, and mutations occur. Producers who notice an unusual tree may propagate it.
Where it grows
Small plantings in Brazil, Central America and Rwanda, usually as a separated micro-lot.
The honest framing
Interesting, rare, and mostly a curiosity. If a bag makes a great deal of the colour, be sceptical.
Brewing it
Filter at light to medium roast, as with any Bourbon.