[jdk11u-dev] RFR: 8213781: web page background renders blue in JEditorPane

[Mangovnik]

Backport of [JDK-8213781](https://bugs.openjdk.org/browse/JDK-8213781) - web page background renders blue in JEditorPane
  
Fixing JEditorPane that for some webpages renders the background blue instead white. E.g. http://www.google.com/
  
Clean backport.  
Passed tier1 tests.  Existing failures are the same as on the unpatched code, they are unrelated.
Passed gtests.  
  
GH Actions are passing.

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Commit messages:
 - Backport f3c10c8049008a170af997d9f5bd70ab6805b243

Changes: https://git.openjdk.org/jdk11u-dev/pull/3118/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=3118&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8213781
  Stats: 129 lines in 2 files changed: 129 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/3118.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/3118/head:pull/3118

PR: https://git.openjdk.org/jdk11u-dev/pull/3118