(Accessibility) Management/Security/Roles - Color Contrast failure on control focus

[barlowm]

Note: This is exhibited on all drop down controls that have the "euiFormControlLayoutClearButton" on this page

Steps to reproduce

1. Log in to Kibana
2. Using keyboard only, navigate to the Management / Security / Roles page
3. Click Create Role
4. Click Add space privilege
5. Select a spaces in spaces field
6. Press <TAB> to focus on the "X" button

Actual Result
Focus identifier on the "X" control fails color contrast (contrast of 1.64:1, minimum contrast ratio should be at least 4.5:1) (see screenshot)

There is no identifier (tool tip or other identifying characteristic) to tell the user that clicking the button will "clear" the the "spaces" field

Expected Result
The focus identifier should meet contrast requirements for the icon not the page background (identifier is too dificult to identify the way it is)
There should be some identifying characteristic to let the user what this control will do as it is separate and distinct from the "X" delete single entry for each value in the field

Meta Issue
Accessibility Audit for Kibana 7.0

Kibana Version:
7.3.0

OS:
Tested on Windows 7.

Browser:
Tested in Chrome.

Screen reader: [if relevant]
None

Relevant WCAG Criteria: WCAG Criterion
1.4.3 Contrast (Minimum) - Level AA

Relevant ARIA spec: WAI-ARIA Authoring Practices 1.1
N/A

[elasticmachine]

Pinging @elastic/kibana-security (Team:Security)

[myasonik]

Closing in favor of an issue in EUI: elastic/eui#2841

[elasticmachine]

Pinging @elastic/eui-design (EUI)