RGB Colours not coming out as expected

Hi There,

I was trying to make myself a simple tool to display an integer using resistor colours, but some of the colours I was choosing display completely wrongly.

In the example here, I used the Colour Picker to choose (143, 72, 19), which is a fairly rich brown colour, shown correctly in the two little squares in the bottom-left of the picker, but when I then use the Custom Preview to apply this to a plane surface, the colour comes out as a much lighter orange colour.

Some of the other colours I was using are fine, but Orange (247,164,47) comes out as very similar to Yellow (255,255,0).

What am I doing wrong? Is this a Windows issue?

See component at the end of:
ResistorColoursTest.gh (19.8 KB)


check if in Rhino you are in wireframe or shaded view



close enough I guess :slight_smile:

Sigh! I had not appreciated that wireframe view would change the colours. Thanks so much - shaded or rendered view seems to fix the problems!

Yes, I should go back and re-sample the colours from some recognised pallet for resistor colours. Your orange is better than mine.

Thank you again,


Fixed the colours to agree with Wikipedia, and converted to cluster:

ResistorColours2.gh (19.1 KB)

Now, back to the real project!

Thanks again,


1 Like

Conversion from Color to Material is incomplete.
If you need a constant “flat” color, do something like this:

1 Like

Aha! More Black Magic!

I find these automatic type conversions that appear to ‘just work’, but may actually do something unexpected, to be so confusing! Colour → Material worked for some colours and failed for others, but only in wire-frame mode!

But yes, fixing Diffuse and Specular to Black and using only Emission for the colour give the right answer in all display modes.

Many thanks!