Error color parameter in URL is not effective

[wangweixuan]

Describe the bug
The error parameter in URL, e.g. https://material-foundation.github.io/material-theme-builder/?error=%2300ff00, is not effective like primary or secondary parameters.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://material-foundation.github.io/material-theme-builder/?primary=%2300ff00
2. See that the primary color is #00ff00, as is specified in the URL.
3. Go to https://material-foundation.github.io/material-theme-builder/?error=%2300ff00
4. See that the error color remains the default color.

The "Copy link" button on the export page generates links like http://material-foundation.github.io?primary=%23B33B15&error=%2300FF00&colorMatch=false, which suggests that the error parameter should work. (The link itself does not work due to #338.)

Expected behavior
The chosen error color should be recovered after opening the link.