SG 1078 (issued 1981) was certainly not printed in two colours!
It looks strange, but I think the poor condition of the stamp may be the cause of the strangeness. The general reddish colour may be the result of soaking or prolonged exposure to light. Compare this, from my own collection, which I think is closer to the correct colour, "deep dull purple", but still displays some uneven colouring in places:
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