Tested the issue on chrome reported version# 68.0.3440.106, using Mac 10.13.6 with steps mentioned below:
1) Launched chrome reported version and opened Devtools
2) Selected an element, right clicked on it and clicked on 'Edit Attribute'
3) Able to see selected element in highlighted colour

@Reporter: Please find the attached screencast for your reference and provide your inputs on it, if possible could you please provide the screencast of the issue which help in better understanding.

Thanks!

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The steps are replicated correctly. You'll notice in your screencast that the text color of the attribute in the 'editing' state no longer has syntax hightlighting.

In my screencast, I removed the css properties that override the syntax highlighting.

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	syntax-highlight-persist.mp4 9.4 MB View Download

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For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Tested the issue on chrome reported version# 68.0.3440.106 using Mac 10.13.6 with steps mentioned below:
1) Launched chrome reported version and opened Devtools
2) Selected an element, right clicked on it, clicked on 'Edit Attribute' and observations as shown below:
Observations: As shown in screencast, when right clicked on "class" attribute and clicked on edit attribute, seen only "class" attribute highlighting, in the same way when i right clicked on "issue_text" value, seen only that text highlighted and when right clicked on "=" symbol, then total value "class="issue_text" is highlighted.

@Reporter: Please find the attached screencast for you reference and let us know if you are also pointing the same which i have captured in the screencast and provide your feedback on it.

Thanks!

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	875668.mp4 2.3 MB View Download

That is an interesting and related observation, but not what I was trying to articulate.

Attached is an example of what an attribute in edit state looks like currently and what I expected. The difference being that the color of the text (the syntax color) persists between the view and edit states

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	ss-2018-08-21-08-01-08.png 21.9 KB View Download

Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Able to reproduce the issue on chrome reported version# 68.0.3440.106 and on latest chrome# 70.0.3530.0 using Linux 14.04, Mac 10.12.6 and Windows-10. As this issue is seen from M-60(60.0.3112.0), hence considering this issue as Non-Regression and marking it as Untriaged.

Thanks!

This is a feature request. Based on how the text is processed, its not easy to add syntax highlighting. It is certainly doable, but I don't think its worth the maintenance cost.

>Did this work before? Yes m30 something I think. Pretty long time ago. 

Are you sure?
I don't see it in Chrome 5, 24-36, 44, 50, 60.

The syntax is already highlighted. There are css selectors that are specifically overridding it. 

https://github.com/ChromeDevTools/devtools-frontend/blob/master/front_end/elements/elementsTreeOutline.css#L209

The removal of that.. along with it's respective entry for the dark theme would 'fix' it.

@woxxom - I don't recall the exact milestone. Maybe a blame on the file above would be telling. I started theming devtools in 2013 and I distinctly remember it changing because I could no longer 'unset' the color override.