Bugzilla

**Affected versions**
* 88.0a1(2021-03-25), 87.0b2

**Affected platforms**
* Windows 10;

**Steps to reproduce**
* not sure how to trigger it consistently, happened slow-loading internet spikes;
1. Launch Firefox, enable DevTools set it to dark theme;
2. Open the Stylesheet tab;
3. Load any webpage; 

**Expected result**
* stylesheet section is populated with data;

**Actual result**
* the eye icon appears pixelated or deformed at times while loading;

**Regression range**
* cannot get a proper regression range until the message can be consistently triggered;
* Last good: 2019-09-27 build that I managed to confirm;

**Additional notes**
* attached recording to best illustrate the issue.

**Affected versions**
* 88.0a1(2021-03-25), 87.0b2

**Affected platforms**
* Windows 10;

**Steps to reproduce**
* not sure how to trigger it consistently, happened slow-loading internet spikes;
1. Launch Firefox, enable DevTools set it to dark theme;
2. Open the Stylesheet tab;
3. Load any webpage; 

**Expected result**
* stylesheet section is populated with data;

**Actual result**
* the eye icon appears pixelated or deformed at times while loading;

**Regression range**
* cannot get a proper regression range until the message can be consistently triggered;
* Last good: 2019-09-27 build that I managed to confirm;

**Additional notes**
* attached "good version" screenshot;
* attached recording to best illustrate the issue on the next comment.

**Affected versions**
* 88.0a1(2021-03-25), 87.0b2

**Affected platforms**
* Windows 10;

**Steps to reproduce**
* not sure how to trigger it consistently, happened slow-loading internet spikes;
1. Launch Firefox, enable DevTools set it to dark theme;
2. Open the Stylesheet tab;
3. Load any webpage; 

**Expected result**
* [ x ] close button is visible;

**Actual result**
* with the current color scheme the [ x ] close button is not visible on Dark Theme (dark grey background + black icon);

**Regression range**
* cannot get a proper regression range until the message can be consistently triggered;
* Last good: 2019-09-27 build that I managed to confirm;

**Additional notes**
* attached "good version" screenshot;
* attached recording to best illustrate the issue on the next comment.

**Affected versions**
* 88.0a1(2021-03-25), 87.0b2

**Affected platforms**
* Windows 10;

**Steps to reproduce**
* not sure how to trigger it consistently, happened slow-loading internet spikes;
1. Launch Firefox, enable DevTools set it to dark theme;
2. Open the Stylesheet tab;
3. Load any webpage; 

**Expected result**
* Stylesheet error  - [ x ] close button is visible;

**Actual result**
* with the current color scheme the [ x ] close button is not visible on Dark Theme (dark grey background + black icon);

**Regression range**
* cannot get a proper regression range until the message can be consistently triggered;
* Last good: 2019-09-27 build that I managed to confirm;

**Additional notes**
* attached "good version" screenshot;
* attached recording to best illustrate the issue on the next comment.