How to change color in a line drawing

Question

I have a SVG drawing with black foreground and white background.

What is the easiest way to change foreground to white and the background to transparent (in InkScape or similar free program)?

Answer 1

There is no easy single step procedure do do that! There is however a multi-step procedure available using InkScape.

To change the background to transparent go to File > Document Properties > Background and check the alpha channel (A). Set the value to 0 (zero).

However, if your drawing contains white objects overlaying another object, you should as an intermediate step set the background to a special color, say pink semi-transparent, to easy the following steps.

Changing the white objects color to transparent will not work, as the outer objects color will shine through (in my case black).

I used the following steps:

Initial:

Step 1: Mark the outer outer (black) object, then shift mark the inner (white) object.

Step 2: Select Path > Difference (or Ctrl+-).

The inner object is deleted in the process, which is what we want here!

Repeat step 1 and 2 for other white objects.

Step 3: Fill all black objects with white.

Step 4: Change the background to fully transparent. Now your drawing disappears and appears all white. This is okay!

Finally save and export as PNG-image.