RGB values for colours in Rhinoceros

I used colour RGB 0,0,19 in Rhinoceros. When this is exported to an image the colour code in the image is RGB 0,0,78.

Anybody that can explain that?

Regards
Oystein

‚ÄúExported‚ÄĚ how? What color? A render? That‚Äôs how lighting works.

Printed it as an image (png). Colour in image looks correct but has different RGB value.

If you are creating an image of objects in shaded mode, of course the color will never be the same as the applied color, because of the lighting/shadows. The only way to have a guaranteed object color on export is with curves or hatches, not with anything that is shaded or rendered.

It was hatches and text.

Okay but in what context? Good grief show us a file or something, you could not be giving less information.

I wouldn’t expect anything to be interpreted exactly when exporting to an image format, as there are some other effects going on such as anti-aliasing etc. which could affect the color rendition - remember, in this case you are just sending out screen pixels. If you need exact export colors, you will need to print curves/hatches/text vector to PDF or similar.

All hatches and text got their colour by the layer RGB 0,0,19 as far as I can see… which is dark blue. Both in an image editor and in office this colour comes up as RGB 0,0,78 when reading the png image exported from Rhino.

I wanted to use the same colour in a Word/Powerpoint template. That is why I wonder.

How exactly did you ‚Äúexport‚ÄĚ this stuff to a png?

Print to image file.

19 or 191? 0,0,19 will be almost black. ‚ÄúDark Blue‚ÄĚ in Rhino is 0,0,191.

I view-captured some hatches with pure red, green, and blue as an image using lossless TIFF format - they all came over perfect. Tried PNG as well, same. Don’t use JPEG, the compression algorithm may alter colors.

‚ÄúPrinting to an image file‚ÄĚ is actually ‚ÄúRendering,‚ÄĚ so lighting will be applied. I don‚Äôt know why it even exists, it just causes confusion like this. It‚Äôs a render.

Also tried printing to a .png via the print dialog, hatches came over exactly the same color into Photoshop. Even in perspective view…

I imported an image and i supposed to use the colour in that so i used the pipette and it showed rgb 0,0,19 (#000013).

As i understand the render settings while influence the result?

You’ll want to set Gamma for linear workflow to 1. Your rendering should match completely the values you pick for input colors.

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Thanks for all answers.

You are right Nathan. It is about the gamma value in the render settings. I have never changed that so I guess 2.2 is the standard value. When I turn off that the colour shown is very close to black (0,0,19). With gamma on 2.2 the same rgb value gives dark blue equal to rgb (0,0,78).

Hello Helland,

I am glad matters seem to be working out. But I kindly do agree with Jim:

In fairness, [please let me know if I am mistaken] posting a file that demonstrates the issue, immensely helps those trying to help and those trying to learn [and hopefully are of the mindset who ‚Äúpayback‚ÄĚ when they can]. If the file is confidential perhaps then one could create a shame file that demonstrates the problem and then the NDA is not broken. Of the many strengths this form has, is that it is populated with good soul experts who help pro bona and McNeel staff who likewise good souls, go the ‚Äúextra mile‚ÄĚ to help. This form now represents a database about a software program that is perhaps unprecedented.

Thank you,

Andy

p.s. If the file is confidential it is my understanding that you can send a file confidential to McNeal. You could even check with the party (s) of the NDA to see if sending the file to McNeel is acceptable to the party (s) first.