macOS Sierra Preview: Have the highlight colours for PDFs changed?

The highlight colours in my Preview application appear darker just after updating to macOS Sierra Version 10.12.1. Is this a change introduced in the update or is this a bug?

Note: I'm using Preview Version 9.0 (909.6)

Yes, the colors have darker shades in macOS Sierra, compared to El Capitan. What you are seeing is not a bug.

This is true for all colors (yellow, blue, green, purple, and pink).

It's not a bug obviously. Maybe Apple changed it because they could, and so they did. Hooray Apple! Actually, it might be because the newer Apple computers are so much more brighter than the older ones, they skipped the pastel highlightning colours in Preview. Maybe you'd like to buy a new Apple computer now? :/