Ansi color in jenkins pipelines

In all cases ensure you have the ansi-color plugin installed

In Declarative Pipelines

You need to add an option for ansiColor()

pipeline {
  options {
    ansiColor('xterm')
  }
  
  // pipeline goes here
}

In Scripted Pipelines

Simply put ansiColor() {} around everything

 ansiColor('xterm') {
    // pipeline goes here
 }