Canvas extension color from Checkered to white?

[stillazoe]

I would like to change the canvas extension to white from checkered.

I have learned how to add a border around a photo by adjusting canvas size. 

In that dialogue box, the "canvas extension color" down arrow is not clickable.

The color box at the very bottom left currently shows two overlapping white boxes.  Changing either of these two colors has no effect on the border.

I am working in RBG mode.

Thanks for your help.  Trying to send this photo to the printer....

[hatstead · Accepted solution]

Go to Image>resize>canvas size. 

In this dialog you can define the extension of the width & height. Note the dropdown to access the scale, e.g. inches, percent, etc.

If you wish to extend just one border, use the Anchor button

At the bottom you can select the color to suit.

If this is not what you are after, let us know,

[stillazoe]

Hello and thanks for this response.

That's exactly what I'm after, but if you notice, in my original note, I said that the "Canvas extension Color" is not clickable.  It shows "background" and nothing happens if I click the little down arrow to the right.  

Does the fact that my image is png. format make any difference?

[Jeff Arola]

For the Canvas Extension Color to be active your image needs to have a Background Layer.

You can go to Layer>Flatten Image or make a Background from the selected layer by going to Layer>New>Background from Layer.

[stillazoe]

Thank you Jeff!  After I figured out how to make a background from a layer, it worked like a charm!