Create blank image in Imagemagick

Question

White background

convert -size 800x800 xc:white white.png

xc: used to mean “X Constant Image” but now is just a shorthand for canvas:. This means you can also use:

convert -size 800x800 canvas:white white.png

and because “white” is the default value if no color is provided, you can also use:

convert -size 800x800 xc: white.png
convert -size 800x800 canvas: white.png

If by “blank” you mean “transparent”, just use that word as the color:

convert -size 800x800 xc:transparent transparent.png

Answer made possible by ImageMagick v6 Examples and How to create a new image?