How to reproduce:

package test

case class SomeCaseClass(id: Long, canonicalName: String, names: List[String]) {
  private val or = s"(${(canonicalName :: names).map(_.toLowerCase).distinct.mkString("|")})"
  val matchRegex = s"(?ui)\\s+$or\\s+|\\s+${or + "$"}|^$or\\s+".r
}

trait RegExFail {

  val regex = """\s*\([^)]*\)""".r
  
  val color: Color

}

CTRL+SHIFT+O (organize-import) OR Choose "java.awt.Color" from popup when entering "val color: Color"

Will produce:

package test

import java.awt.Color

case class SomeCaseClass(id: Long, canonicalName: String, names: List[String]) {
  private val or = s"(${(canonicalName :: names).map(_.toLowerCase).distinct.mkString("|")})"
  val matchRegex = s"(?ui)\\s+$or\\s+|\\s+${or + "$"}|^$or\\s+".r
}

(trait RegExFail {

  val regex = """\s*\([^)]*\)""".r
  
  val color: Color

}