[Qgis-user] colorramp starting from white

[Raymond Nijssen]

Hi Anita, Harrissou,

Yes, this is what I mean. I think the intermediate colors (stops) make 
the ramp more beautiful, cause this way you can adjust the hue, 
saturation and value in curved ways along the ramp, instead of doing 
linear interpolation between 2 colors. I also figured out that "our" 
single color ramps  (Greens, Reds, ..) exactly match the colorbrewer scheme.

But maybe having only 1 value in the middle and doing something 
"spliney" would work? Or a feature that strips the first class, as Anita 
suggested?

Another easy option, we also have color ramps called RdBu. Maybe have 
WhRd (for White-Red?) and Rd (for Pink-Red)?

Looking at all the color ramps now, I realize that almost all contain 
white (or black). The single colored ramps start from white and the 
double colored have white in the middle.

Raymond


On 15-06-2020 23:06, DelazJ wrote:
> Hi,
> Trying to quickly change the starting color of a default continuous 
> ramp, I realize that changing the first color is not enough, you need to 
> change/remove the intermediate ones also, in order to have something smooth.
> So, question: why do we need stops in a color ramp that is supposed to 
> be continuous from color A to color B? Could the default continuous 
> color ramps not only have a start color and an end color? Nothing else?
> 
> Regards,
> Harrissou
> 
> Le lun. 15 juin 2020 à 22:48, Anita Graser <anitagraser at gmx.at 
> <mailto:anitagraser at gmx.at>> a écrit :
> 
>     15 Jun 2020 15:53:43 Raymond Nijssen <r.nijssen at terglobo.nl
>     <mailto:r.nijssen at terglobo.nl>>:
> 
>      > Am I the only one who would like the color ramps in QGIS to NOT
>     start from (super nearly) white, but from a light version of the color?
> 
>     Quite the contrary. I often have the need to change the starting
>     color to real white or even transparent.
> 
>     It's probably one of those cases of "it depends!"
> 
>     In choropleth maps, it's important to distinguish between non and
>     the lowest class. However, for heatmaps and similar viz, a smooth
>     transition from white is often desired.
> 
>     Conclusion: the starting color should be really easy to change.
> 
>     Regards
>     Anita
> 
>      >
>      > For example, "Reds" should go from (light) pink to red.
>      >
>      > Currently, the first class in my legend always looks white, as
>     many other parts of my map often do. Therefore it is hard to see
>     where my data is and where not.
>      >
>      > Another thing, changing it manually is hard because of the 7
>     stops in the ramps.
>      >
>      > I'm happy to figure this out and make a PR, but would like to
>     know other's opinions first.
>      >
>      > Regards,
>      > Raymond
>      >
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