Canvas borders are not supported in color mode except RGB

[dasom_Lee]

Canvas borders are not supported in other color modes except rgb mode.

I usually work with cmyk, so I make the background white and it's so inconvenient to see the image in advance.

I checked the symptoms on several computers and someone said they don't have these symptoms.
Can you give me 5 seconds to test it for me? Is there a computer that develops similar symptoms?

I use the latest version of Windows 10 and Photoshop. I asked the customer center about this issue twice and Adobe confirmed it, but it was not reflected in the update.

[D Fosse]

Start by telling us exactly what you mean by "canvas border" and how you make it.

[dasom_Lee]

 

Apart from the rgb mode, the dividing line on the canvas disappears.

[c.pfaffenbichler]

I can reproduce the issue (Adobe Photoshop 26.3.0 on  Mac OS 14.6.1); the setting from Preferences > Interface > Border does only seem to apply to RGB images. 

But … 

If the work is print-oriented I would discourage using a white background. 

The second lightest Color Theme and a light gray background should be fine. 

[D Fosse]

OK, that's the on screen canvas border, not part of the image.

And yes, you're right. It does disappear when you convert to CMYK. I have no idea why...

[dasom_Lee]

Only RGB mode supports boundaries. Is it verrrrry hard to support boundaries in other modes?

[dasom_Lee]

I want to know how my output looks when printed on white paper. Boundaries are supported in rgb mode, is there a reason why not in other modes?

There is a problem that other operating systems are reproduced too, and someone says this is no problem.

I think he's lying.

[c.pfaffenbichler]

»Boundaries are supported in rgb mode, is there a reason why not in other modes?«

None comes to mind, that’s why I added my vote to the Bug Report. 

»There is a problem that other operating systems are reproduced too, and someone says this is no problem.

I think he's lying.«

I explicitly mentioned that I can reproduce the issue on Mac, so who said what exactly? 

[Mi Tech_Digital 2025]

If you're trying to add canvas borders in Adobe Photoshop but it's not working, it's likely because your document is in a color mode other than RGB (such as CMYK, Grayscale, or Indexed Color). Photoshop only supports canvas borders in RGB mode.

How to Fix It:

1. Check Your Color Mode – Go to Image > Mode and see if it's set to something other than RGB.
2. Convert to RGB – If it's in CMYK, Grayscale, or another mode, select RGB Color to enable canvas borders.
3. Retry Adding Borders – Now, go to Image > Canvas Size, select a border color, and it should work properly.

If you're working on a print project that requires CMYK, you can switch back after applying the border.
I faced a similar problem while wokring for my website Magis tv para pc , i followed the same pattern and it worked for me.  Hope this helps! 😊 

[dasom_Lee]

The post together on the kr community says someone can't recreate it.

link

[dasom_Lee]

It's an alternative, but not a workaround. I often use the cmyk mode and customized a white background like print paper. I can't even do the cropping properly. 😕

[c.pfaffenbichler]

Photoshop only supports canvas borders in RGB mode.

Working in RGB mainly (and with a gray background anyway) it affects me little but I understand the original poster’s consternation about the distinction as it does not seem technically unavoidable while offering no apparent benefit.