What about the "Reading List" menu entry?
Should the menu entry and the tools menu always be the same color?
What if we restart Chrome?

They shouldn't always be the same colour. 

The menu entry will remain blue until pressed on the local device or the reading list view is entered on a different device. 

The three-dots menu will remain blue until pressed on the local device or the reading list view is entered on a different device.

IMHO, this is what makes the most sense from a user's perspective. 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bc9d2d7b3acde39d666adca91fdb897535455b5a

commit bc9d2d7b3acde39d666adca91fdb897535455b5a
Author: olivierrobin <olivierrobin@chromium.org>
Date: Tue Dec 06 10:40:43 2016

Add Unseen state to Reading List Entry

The new logic requires a flag in each entry, and this flag must be synced.
Add a state in ReadingListEntry.
When an entry is created, it is UNSEEN.
It cannot be set back to this state.

The logic is
IsRead() := state_ == READ
HasBeenSeen() := state_ != UNSEEN

BUG= 671185 

Review-Url: https://codereview.chromium.org/2557443003
Cr-Commit-Position: refs/heads/master@{#436563}

[modify] https://crrev.com/bc9d2d7b3acde39d666adca91fdb897535455b5a/components/reading_list/ios/proto/reading_list.proto
[modify] https://crrev.com/bc9d2d7b3acde39d666adca91fdb897535455b5a/components/reading_list/ios/reading_list_entry.cc
[modify] https://crrev.com/bc9d2d7b3acde39d666adca91fdb897535455b5a/components/reading_list/ios/reading_list_entry.h
[modify] https://crrev.com/bc9d2d7b3acde39d666adca91fdb897535455b5a/components/reading_list/ios/reading_list_entry_unittest.cc
[modify] https://crrev.com/bc9d2d7b3acde39d666adca91fdb897535455b5a/components/reading_list/ios/reading_list_store_unittest.mm
[modify] https://crrev.com/bc9d2d7b3acde39d666adca91fdb897535455b5a/components/sync/protocol/proto_enum_conversions.cc
[modify] https://crrev.com/bc9d2d7b3acde39d666adca91fdb897535455b5a/components/sync/protocol/reading_list_specifics.proto

+ Helene who's thinking about state indication as part of her overflow animation explorations.