My logo is colored, and the client asked me to make a white version of it. But unfortunately the logo’s thickness increases in this white version. How can I overcome this?
It is a known optical effect that light lines on a dark background appear thicker than vice versa. Here is a documentation of this effect for a font that comes in two variants to compensate for it.
You can account for it by making the light-on-dark strokes have approximately 0.92 the width of the dark-on-light strokes. (The value is empirical and seems to match the proportions in said font.)