I've a image that's pretty dark, and I would like to make it more clear while respecting the color, my intention here was to create a new layer with white background and tune the transparency until I get the wished color.
UPDATE
The way I opted was to create a new solid white layer

New -> Generated Layer -> Color (choose white here)

Then on the Opacity slider within layer options choose a proper transparency (20% in my case)

Thanks

To get such a layer, you can either create a layer and fill it with white, or use a white color generator layer -- but that won't lighten your image.

Thanks boud, great help as usual!