The Behlens Solar-Lux Lemon Yellow is very bright when first applied, but under epoxy and varnish it mellows. Its still bold, but doesn't quite melt your eyes.

In the Behlens line the "Medium Wheat" could still be called yellow but has a hint more orange in it. Not quite as bright.

Of course your results may vary a lot depending on the base color of the particular Okoume you are starting with.