The new user interface for Kdenlive's Lift/Gamma/Gain effect got a complete redesign. Instead of the old sliders-and-input-boxes generic user interface, you now get color wheels and tone sliders for lift, gamma, and gain. This surely is much more intuitive than the older generic user interface.
At least to the extend that lift/gamme/gain is intuitive in itself.
So, for the technical background on grading controls, such as the lift/gamma/gain effect, I highly recommend reading Alexis van Hurkman's blog post What's in a Name? On the differences among grading controls and operational ordering.
Anyway, the new user interface should definitely please the «Generation PhotoShop». ;)