I'm just curious about the Saturation effect. (Add Effect>Color>Saturation)
It works perfectly fine, but why is 125 the standard setting? what units are these?
I would have thought a percentage scale with 100 as standard would have made sense.
Am I missing something? Does anybody have an explanation for this?

http://www.mltframework.org/bin/view/ML ... saturat0r|

title: Saturation
description: The saturation value
type: float
readonly: no
required: no
minimum: 0
maximum: 1
default: 0.125
widget: spinner

The freiOr default is 0.125 or 12.5 %
So it looks like the kdenlive units are in 10ths of a percent

thanks for the link - though this seems counterintuitive to me, and I would assume to new users of Kdenlive as well.
For most practical color work, when adjusting a clip's saturation, you would not be thinking on an absolute scale of 0% (black and white) to 100% (primary colours, the maximum possible saturation) unless you were aiming for an over-the-top garish effect.
Normally you would make a styistic choice to slightly reduce or increase the saturation relative to the current saturation of the existing clip. Perhaps reduce by 10 percent for a more filmic, old-style look or increase 10 percent for a fun, bright feel. Most of the uses of the saturation effect would stay relatively close to this '125' default value.
Depending on camera settings and the lighting of the shot, you'll have different saturation levels for every scene/project - sometimes Frei0r's "12.5% Saturation" might be very colourful, sometimes more sombre.
Currently it is somewhat confusing. The first time I added the saturation effect I wanted to slightly desaturate the clip. Seeing the value '125' I assumed that I had added an 'Increase Saturation' effect and dialed it back to 90, which of course was far less saturation than I was looking for.

I think it would make a lot more sense for kdenlive to interpret frei0r's "125" as "100%" - for example:
Frei0r --- 0 125 250 375 500 625 750 875 1000
Kdenlive 0 100 200 300 400 500 600 700 800
This would be easier for new users to understand, and be in line with norms used in other image manipulation and post production programs.
Does this make sense? Is it easy to implement? how do I submit this suggestion properly to the dev team?

To lodge a feature request use http://www.kdenlive.org/mantis/

done. thanks!
http://www.kdenlive.org/mantis/view.php?id=3177