LabVIEW 2010 icon editor -- why is white not white

[warren_scott]

OK, so I'm creating an Icon in LV 2010.

I want a white background. 

So I choose the white color in the palette.  But that doesn't quite look like white (a little darker than white).

so I go get a custom color, and set it to 255/255/255 (R/G/B).  add it to my custom colors.  hover over it quickly with the mouse and see that it is actually 255/255/255.

Then I go back to the actually icon editing, and make sure my color selection (foreground/background) is both WHITE (255/255/255).

I draw a box.

The box isn't white!!!

the box is drawn with colors 246/246/246 (R/G/B) not 255/255/255!

Go create another custom color of 255/255/254.

Draw the box again.

Box looks white, but it is actually 255/255/254 (what you would expect to get).  Close enough for me to use, so I can get on with making my icons, but I just need to remember to not try to actually set the color to 255/255/255 -- actually use something ever so slightly different. 

Best I can figure out -- if you hover over a transparent section, you see the color go to 255/255/255, so LV must be using 255/255/255 as transparent.  But then it says that color is 255/255/255, and it's not, it's transparent.  So the color should be shown as T/T/T so I don't need to know the special magical decoder of 255/255/255 = transparent to see if one single pixel is transparent color or not.

End of rambling and venting, and on to the real question:

What's special about taking 255/255/255 white and converting it to 246/246/246 instead of something closer like 254/254/254?

[Darin.K · Accepted solution]

The Icon Editor thinks it is doing you a favor, and it probably really is given the (perhaps outdated) method LV uses for transparency on the BD.  By design, any "white" on the outside of a BD object (ie. icon) is considered transparent and not part of the object as far as clicking is concerned.  I have also discovered the hard way that "white" means any pure grey (R=G=B) with R,G,B > 246.  Tweaking the B value is one way to avoid this (as you have discovered).

You can get some very interesting effects when LV thinks your entire subVI is transparent.

[JÞB]

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@Darin.K wrote:

You can get some very interesting effects when LV thinks your entire subVI is transparent.

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Sounds like a candidate for things you should not do-  especially with native recursion.  ~~~I'm not going to try it ~~~

[warren_scott]

That's pretty crazy!  Learn something new every day.