With color support, core Maven and plugins do general message colorization (or more high-level "message styling" through maven-shared-utils)
slf4j provider however has to add color:
- for log level output (DEBUG/INFO/WARNING/ERROR)
- for stacktrace rendering
That's why we use Gossip slf4j provider: it has sufficient little extension points to add this, with just a little bit of code (see http://maven.apache.org/ref/3-LATEST/maven-embedder/apidocs/org/apache/maven/cli/logging/impl/gossip/package-summary.html ) and configuration
The issue with switching to Gossip slf4j provider is that people don't know it and it does not have the same features as slf4j-simple (missing relative timestamps and configuration with CLI: see http://mail-archives.apache.org/mod_mbox/maven-dev/201607.mbox/%3CCAK8jvqxYNK4weM2Frp4Brg3J7EybyjBiCsSRdGuNMQhYAG728Q%40mail.gmail.com%3E ), the configuration file is not the same (name nor content).
But the extension points are not that big: if slf4j-simple provider just made a few methods protected instread of private, it would be extensible
What if we just copy slf4j-simple to change the signatures and create small extension classes? The license permits it, we can try it and eventually see with slf4j if the modification can go into official release