Sebastien, you mentioned that you also have some concerns about a11y and user preference here - can you please explain?

I was curious if the selection/hover state was bound somehow to a system user preference.

In the past the dropdown colors were all system colors.  I don't know whether that's still true at the moment, but that's what we've typically considered ideal.

If possible, I'd like to align with our visual direction, i.e switch to blue links.
Windows is the only platform diverging at the moment.

It's also the only OS that really cares about letting users tweak colors :).

We might be able to do something smart here, but I'd have to look at it, and also consider accessibility issues.  In any case this seems minor, not P1.

I'm not asking to disable the color tweak, hence me #2 comment. I'd like to "Default" or "out of the box" experience to be similar, if possible, to Chrome elsewhere. I'm not even sure the decision to have green links wasn't a pure design decision at the time over OS consistency.

Right, the issue is that it's hard to distinguish between whether a user has customized their colors or not -- the system doesn't tell you want the "default" colors are, just what the current colors are, and the built-in defaults change over time.

Hover doesn't have a system color, but selected row, text, background, and link all do.  Maybe I can use the MD colors if they are "sufficiently close" to the system colors or something.

Ok. My issue in particular is on the bright green used when selected. I don't see that anywhere else in the OS. Also this shade of green on this blue is not accessible (2.2 on contrast test). 

I see that we are using the new Chrome green for normal links #0B8043. 

Could we change that to #3367D6 and switch from the current bright green to #FFF when the row is selected? This will match what we do in the omnibox itself and bump the accessibility score from 2.2 to 2.9, which is a bit better.

See proposal attached.

Deleted: proposed.png 115 KB

	proposed.png 115 KB View Download

Let me look into all these colors.

Also, little nitpick, if we are keeping the blue selected state, we should paint the selected row icon white as well. 

 Issue 566071  has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9b55ff2e61b462dfb0c9b2ee86d43ea26df9a135

commit 9b55ff2e61b462dfb0c9b2ee86d43ea26df9a135
Author: pkasting <pkasting@chromium.org>
Date: Fri Jun 17 18:02:49 2016

Theme code cleanup.

* Remove some color constants that are never used.
* Remove some MD-specific constants in the Aura theme that are exactly the same
  as the non-MD constants.
* Pull pre-MD-specific cases out of the Windows code to avoid repeated
  conditional breaks.
* Rename/reorder Windows constants a bit in preparation for changing how MD
  works.

BUG= 597754 
TEST=none

Review-Url: https://codereview.chromium.org/2076893002
Cr-Commit-Position: refs/heads/master@{#400453}

[modify] https://crrev.com/9b55ff2e61b462dfb0c9b2ee86d43ea26df9a135/chrome/browser/ui/libgtk2ui/native_theme_gtk2.cc
[modify] https://crrev.com/9b55ff2e61b462dfb0c9b2ee86d43ea26df9a135/ui/native_theme/common_theme.cc
[modify] https://crrev.com/9b55ff2e61b462dfb0c9b2ee86d43ea26df9a135/ui/native_theme/native_theme.h
[modify] https://crrev.com/9b55ff2e61b462dfb0c9b2ee86d43ea26df9a135/ui/native_theme/native_theme_dark_aura.cc
[modify] https://crrev.com/9b55ff2e61b462dfb0c9b2ee86d43ea26df9a135/ui/native_theme/native_theme_win.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2a5551d69526ecc08d18c3983f085a94d179e95c

commit 2a5551d69526ecc08d18c3983f085a94d179e95c
Author: pkasting <pkasting@chromium.org>
Date: Fri Jun 17 18:52:00 2016

Modify the ommnibox dropdown colors.

* For all platforms: on selected lines, draw the icon using the text color
  rather than calling DeriveDefaultIconColor(), per comment 10 on the bug.
* For Windows: draw selected lines' URLs in white, like the text, instead of
  using GetReadableColor() on the URL color.  In MD, use the MD link blue for
  links instead of the old omnibox-specific green.

There are a few notes worth making.  I elected to make the "white icon" and
"white text" in non-MD as well because the changes are minor and arguably look
better (and it was easier, and non-MD is not very important anymore...).

Also, the Windows color selection code is careful about whether it uses
GetReadableColor() versus PickContrastingColor().  The idea of this is that the
unselected link color should be some kind of blue no matter what the window
backgruond, to indicate a link; so it uses GetReadableColor().  The hovered link
color should still be blue by default, so it can't use GetReadableColor() on the
white (lest it get black instead), but if the hover background happens to be
really dark, it's better to treat this "like selection" in the sense of using a
white URL than to use a light blue.  The selected link color has similar reasons
but in reverse: we want to be white in the default color scheme, but on systems
where the user has a light selection color on an otherwise dark background, it
seems better to use a blue link than a black one.  So in both cases we
PickContrastingColor() between white and blue, which should be a dark enough
color for these to be reasonable choices in most color schemes.

BUG= 597754 
TEST=On Windows, open the omnibox dropdown, and verify that URLs appear blue when not selected, and white when selected.

Review-Url: https://codereview.chromium.org/2077803002
Cr-Commit-Position: refs/heads/master@{#400471}

[modify] https://crrev.com/2a5551d69526ecc08d18c3983f085a94d179e95c/chrome/browser/ui/views/omnibox/omnibox_result_view.cc
[modify] https://crrev.com/2a5551d69526ecc08d18c3983f085a94d179e95c/ui/native_theme/native_theme_win.cc