How to increase contrast?

How to increase contrast?

Hi there,
I recently purchased a Kobo Forma and I’m comparing it to a Kindle Oasis 3 and I find of the Kindle has better contrast. By contrast I mean the grey colour of the e-ink compared to the grey background of the unit when unlit. I find that the more front lighting I use, the more the contrast seems to be reduced.

I have tried increasing the weight of text and I find it’s helpful, but the Kindle Oasis 3 still seems to have better contrast with the same weighting of text. I also noticed that Sony readers seem to have had a contrast feature which does not seem to be built into the kobo. Is there a plug-in?

Thanks