Colour rendering issue on Atom 1.28.0 / Windows 10

Prerequisites

• Put an X between the brackets on this line if you have done all of the following:
  • Reproduced the problem in Safe Mode: https://flight-manual.atom.io/hacking-atom/sections/debugging/#using-safe-mode
  • Followed all applicable steps in the debugging guide: https://flight-manual.atom.io/hacking-atom/sections/debugging/
  • Checked the FAQs on the message board for common solutions: https://discuss.atom.io/c/faq
  • Checked that your issue isn’t already filed: https://github.com/issues?utf8=✓&q=is%%3Aissue+user%%3Aatom
  • Checked that there is not already an Atom package that provides the described functionality: https://atom.io/packages

Description

Since updating to 1.28 the colours throughout Atom are no longer rendering correctly – it appears like the gamma has been altered or something, the contrast is lower and everything is slightly lighter.

Colours are not rendering correctly even in the dev tools. Here’s two I screen-shotted from the “computed” panel:

Examining those colour squares in an image editor you can see that the colour reported as #cc6666 is actually #b36d68, and #1d1f21 is rendering as #232426.

Running with --disable-gpu does have some visible differences:

Note the render tile edges to the right. The darker area is showing the actual correct colour for the editor background.

Steps to Reproduce

n/a – Atom auto-updated, now it’s permanently in this state

Expected behavior: Colours to appear as they are defined

Actual behavior: Colours do not render as per their definitions

Reproduces how often: 100%%

Versions

Atom : 1.28.0
Electron: 2.0.3
Chrome : 61.0.3163.100
Node : 8.9.3

Additional Information

Windows 10
Nvidia GeForce GTX 1070, 398.11 drivers

Everything appears fine on my Mac, which is using the exact same editor and style configuration.