Oil or Varnish that won't change original colour

[bluegaranium]

Just had new stair handrails fitted and bought some clear duck oil to finish them but on the test piece it has made the wood considerably darker. Is there anything that I can use so that the wood will remain the same colour?
thanks

 

[JohnD]

Dry wood is always lighter.

You can use a clear varnish, but it will always look darker, in the same way that the wood will look darker if you wipe it with a wet cloth.