[ferret_users] Creating difference plots with white in the colour bar

[Aisling Dolan <A.M.Dolan08@xxxxxxxxxxx>]

Hi everyone, 

I am trying to plot the difference between two global temperature fields. 
e.g.
fill/lev=(-inf)(-5,5,1)(inf)/palette=blue_darkred temp_mm_1_5m[d=1,l=1] - temp_mm_1_5m[d=2,l=1]

Where the difference is less than 0.5 degrees Celsius, I wanted to shade the area in white - to imply that the difference is not significant.  For consistency with earlier work I would ideally like to incorporate white into the blue_darkred palette.

Does anyone know a simple way of doing this?  Or what combination of RGB colours make up blue_darkred do that I could try and create my own palette?

Apologies if this is obvious, but I am a ferret novice!

Thanks in advance, 
Aisling   


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Aisling M. Dolan
PhD Student
School of Earth & Environment