Re: color names and fill colors

From: David B. Reusch <dbr_at_nyahnyahspammersnyahnyah>
Date: Fri, 26 May 2006 13:25:14 -0400

Hi Mary,

I see smoothly changing grays in the web image with no jump to white
(which rules out my display, I guess). after adding the NhlNewColor my
fill for gray88 is an actual shade of gray, not white, so it looks like
the color map was the culprit. I wasn't actually defining a color map
in my script and I can see how the default doesn't have much grayscale
to work with (and perhaps not setting gsnSpreadColors is contributing to
not being able to find a match?). this is a really simple script with
just a small amount of color (grays, really) so I wasn't giving much
thought to colormaps at all.

thanks!
dave

Mary Haley said the following on 5/26/2006 1:06 PM:
>
> Hi David,
>
> The distinction between gray87 and gray88 should not be that
> noticeable. As a test, can you please go to:
>
> http://www.ncl.ucar.edu/Document/Graphics/Images/ncolors220-263.gif
>
> Is what you see here for gray 87 and gray 88 the same as what you are
> seeing on your screen?
>
> What may be happening is that if the exact color for gray88 is not in
> your colormap, then NCL will use the next closest match. In your case,
> this may very well be white.
>
> You can try adding gray88 to your color map to make sure it is there:
>
> i = NhlNewColor(wks,0.875,0.875,0.875)
>
> Of course, if you do this, and you are setting res@gsnSpreadColors to
> True, then you may also want to set res@gsnSpreadColorEnd to -2 so
> that it doesn't include this new gray color.
>
> --Mary

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Received on Fri May 26 2006 - 11:25:14 MDT

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