diff --git a/bsp/src/mill/bsp/BspContext.scala b/bsp/src/mill/bsp/BspContext.scala
index a9908d77bea..f5439e1eabd 100644
--- a/bsp/src/mill/bsp/BspContext.scala
+++ b/bsp/src/mill/bsp/BspContext.scala
@@ -52,6 +52,7 @@ private[mill] class BspContext(
       }
 
       override def info(s: String): Unit = streams.err.println(s)
+      override def warn(s: String): Unit = streams.err.println(s)
       override def error(s: String): Unit = streams.err.println(s)
       override def ticker(s: String): Unit = streams.err.println(s)
 
diff --git a/contrib/scoverage/api/src/mill/contrib/scoverage/api/ScoverageReportWorkerApi2.java b/contrib/scoverage/api/src/mill/contrib/scoverage/api/ScoverageReportWorkerApi2.java
index 14dc82d6dd1..29150520454 100644
--- a/contrib/scoverage/api/src/mill/contrib/scoverage/api/ScoverageReportWorkerApi2.java
+++ b/contrib/scoverage/api/src/mill/contrib/scoverage/api/ScoverageReportWorkerApi2.java
@@ -10,6 +10,8 @@ public interface ScoverageReportWorkerApi2 {
   interface Logger {
     void info(String msg);
 
+    void warn(String msg);
+
     void error(String msg);
 
     void debug(String msg);
diff --git a/contrib/scoverage/src/mill/contrib/scoverage/ScoverageReportWorker.scala b/contrib/scoverage/src/mill/contrib/scoverage/ScoverageReportWorker.scala
index b536549608c..51ff53b78d8 100644
--- a/contrib/scoverage/src/mill/contrib/scoverage/ScoverageReportWorker.scala
+++ b/contrib/scoverage/src/mill/contrib/scoverage/ScoverageReportWorker.scala
@@ -39,6 +39,7 @@ class ScoverageReportWorker extends AutoCloseable {
     def ctx0(implicit ctx: Ctx): ApiCtx = {
       val logger = new ApiLogger {
         def info(msg: String): Unit = ctx.log.info(msg)
+        def warn(msg: String): Unit = ctx.log.warn(msg)
         def error(msg: String): Unit = ctx.log.error(msg)
         def debug(msg: String): Unit = ctx.log.debug(msg)
       }
diff --git a/core/api/src/mill/api/Logger.scala b/core/api/src/mill/api/Logger.scala
index 51b754e05e3..37f5a34373c 100644
--- a/core/api/src/mill/api/Logger.scala
+++ b/core/api/src/mill/api/Logger.scala
@@ -37,6 +37,12 @@ trait Logger {
    */
   def debug(s: String): Unit
 
+  /**
+   * Prints logging output which represents warnings the user should care
+   * about
+   */
+  def warn(s: String): Unit
+
   /**
    * Prints logging output which represents problems the user should care
    * about
@@ -128,7 +134,7 @@ private[mill] object Logger {
     private[mill] def enableTicker: Boolean
 
     def infoColor: fansi.Attrs
-
+    def warnColor: fansi.Attrs
     def errorColor: fansi.Attrs
     def colored: Boolean
   }
@@ -148,6 +154,7 @@ private[mill] object Logger {
 
       def enableTicker: Boolean = false
       def infoColor: fansi.Attrs = fansi.Attrs.Empty
+      def warnColor: fansi.Attrs = fansi.Attrs.Empty
       def errorColor: fansi.Attrs = fansi.Attrs.Empty
       def colored: Boolean = false
     }
diff --git a/core/internal/src/mill/internal/Colors.scala b/core/internal/src/mill/internal/Colors.scala
index 98b8c48b4aa..99c6fed05b4 100644
--- a/core/internal/src/mill/internal/Colors.scala
+++ b/core/internal/src/mill/internal/Colors.scala
@@ -1,7 +1,7 @@
 package mill.internal
 
-private[mill] case class Colors(info: fansi.Attrs, error: fansi.Attrs)
+private[mill] case class Colors(info: fansi.Attrs, warn: fansi.Attrs, error: fansi.Attrs)
 private[mill] object Colors {
-  object Default extends Colors(fansi.Color.Blue, fansi.Color.Red)
-  object BlackWhite extends Colors(fansi.Attrs.Empty, fansi.Attrs.Empty)
+  object Default extends Colors(fansi.Color.Blue, fansi.Color.Yellow, fansi.Color.Red)
+  object BlackWhite extends Colors(fansi.Attrs.Empty, fansi.Attrs.Empty, fansi.Attrs.Empty)
 }
diff --git a/core/internal/src/mill/internal/DummyLogger.scala b/core/internal/src/mill/internal/DummyLogger.scala
index f3ea93f8afa..e9905692b90 100644
--- a/core/internal/src/mill/internal/DummyLogger.scala
+++ b/core/internal/src/mill/internal/DummyLogger.scala
@@ -14,6 +14,7 @@ private[mill] object DummyLogger extends Logger {
   )
 
   def info(s: String) = ()
+  def warn(s: String) = ()
   def error(s: String) = ()
   def ticker(s: String) = ()
   def debug(s: String) = ()
diff --git a/core/internal/src/mill/internal/FileLogger.scala b/core/internal/src/mill/internal/FileLogger.scala
index b65a669483a..1a0e1ca3ce0 100644
--- a/core/internal/src/mill/internal/FileLogger.scala
+++ b/core/internal/src/mill/internal/FileLogger.scala
@@ -44,6 +44,7 @@ private[mill] class FileLogger(
 
   val streams = new SystemStreams(fileStream, fileStream, mill.api.DummyInputStream)
   def info(s: String): Unit = streams.out.println(s)
+  def warn(s: String): Unit = streams.out.println(s)
   def error(s: String): Unit = streams.out.println(s)
   def ticker(s: String): Unit = streams.out.println(s)
   def debug(s: String): Unit = if (prompt.debugEnabled) streams.out.println(s)
diff --git a/core/internal/src/mill/internal/MultiLogger.scala b/core/internal/src/mill/internal/MultiLogger.scala
index a93c1ac0e5b..970708a5a43 100644
--- a/core/internal/src/mill/internal/MultiLogger.scala
+++ b/core/internal/src/mill/internal/MultiLogger.scala
@@ -27,6 +27,10 @@ private[mill] class MultiLogger(
     logger1.info(s)
     logger2.info(s)
   }
+  def warn(s: String): Unit = {
+    logger1.warn(s)
+    logger2.warn(s)
+  }
   def error(s: String): Unit = {
     logger1.error(s)
     logger2.error(s)
@@ -85,7 +89,7 @@ private[mill] class MultiLogger(
     override def debugEnabled: Boolean = logger1.prompt.debugEnabled || logger2.prompt.debugEnabled
 
     override def infoColor: Attrs = logger1.prompt.infoColor ++ logger2.prompt.infoColor
-
+    override def warnColor: Attrs = logger1.prompt.warnColor ++ logger2.prompt.warnColor
     override def errorColor: Attrs = logger1.prompt.errorColor ++ logger2.prompt.errorColor
     override def colored: Boolean = logger1.prompt.colored || logger2.prompt.colored
   }
diff --git a/core/internal/src/mill/internal/PrefixLogger.scala b/core/internal/src/mill/internal/PrefixLogger.scala
index 4e694b50e18..d8eb0f3219f 100644
--- a/core/internal/src/mill/internal/PrefixLogger.scala
+++ b/core/internal/src/mill/internal/PrefixLogger.scala
@@ -60,6 +60,10 @@ private[mill] class PrefixLogger(
     prompt.reportKey(logKey)
     logger0.info("" + prompt.infoColor(linePrefix) + s)
   }
+  override def warn(s: String): Unit = {
+    prompt.reportKey(logKey)
+    logger0.warn("" + prompt.warnColor(linePrefix) + s)
+  }
   override def error(s: String): Unit = {
     prompt.reportKey(logKey)
     logger0.error("" + prompt.infoColor(linePrefix) + s)
diff --git a/core/internal/src/mill/internal/PromptLogger.scala b/core/internal/src/mill/internal/PromptLogger.scala
index 5c0ef03ca6a..622afae7fff 100644
--- a/core/internal/src/mill/internal/PromptLogger.scala
+++ b/core/internal/src/mill/internal/PromptLogger.scala
@@ -20,6 +20,7 @@ private[mill] class PromptLogger(
     colored: Boolean,
     enableTicker: Boolean,
     infoColor: fansi.Attrs,
+    warnColor: fansi.Attrs,
     errorColor: fansi.Attrs,
     systemStreams0: SystemStreams,
     debugEnabled: Boolean,
@@ -96,6 +97,8 @@ private[mill] class PromptLogger(
 
   def info(s: String): Unit = streams.err.println(s)
 
+  def warn(s: String): Unit = streams.err.println(s)
+
   def error(s: String): Unit = streams.err.println(s)
 
   object prompt extends Logger.Prompt {
@@ -147,6 +150,7 @@ private[mill] class PromptLogger(
     def debugEnabled = PromptLogger.this.debugEnabled
 
     def infoColor: fansi.Attrs = PromptLogger.this.infoColor
+    def warnColor: fansi.Attrs = PromptLogger.this.warnColor
     def errorColor: fansi.Attrs = PromptLogger.this.errorColor
     def colored: Boolean = PromptLogger.this.colored
   }
diff --git a/core/internal/src/mill/internal/ProxyLogger.scala b/core/internal/src/mill/internal/ProxyLogger.scala
index 192139f743f..8337f34b966 100644
--- a/core/internal/src/mill/internal/ProxyLogger.scala
+++ b/core/internal/src/mill/internal/ProxyLogger.scala
@@ -12,6 +12,7 @@ private[mill] class ProxyLogger(logger: Logger) extends Logger {
   lazy val streams = logger.streams
 
   def info(s: String): Unit = logger.info(s)
+  def warn(s: String): Unit = logger.warn(s)
   def error(s: String): Unit = logger.error(s)
   def ticker(s: String): Unit = logger.ticker(s)
   def debug(s: String): Unit = logger.debug(s)
diff --git a/core/internal/test/src/mill/internal/PromptLoggerTests.scala b/core/internal/test/src/mill/internal/PromptLoggerTests.scala
index 51517fc03f5..b88208be6d1 100644
--- a/core/internal/test/src/mill/internal/PromptLoggerTests.scala
+++ b/core/internal/test/src/mill/internal/PromptLoggerTests.scala
@@ -15,6 +15,7 @@ object PromptLoggerTests extends TestSuite {
       colored = false,
       enableTicker = true,
       infoColor = fansi.Attrs.Empty,
+      warnColor = fansi.Attrs.Empty,
       errorColor = fansi.Attrs.Empty,
       systemStreams0 = new SystemStreams(baosOut, baosErr, System.in),
       debugEnabled = false,
diff --git a/runner/src/mill/runner/MillMain.scala b/runner/src/mill/runner/MillMain.scala
index 9e59cdc79ed..00e93bd3b5c 100644
--- a/runner/src/mill/runner/MillMain.scala
+++ b/runner/src/mill/runner/MillMain.scala
@@ -372,6 +372,7 @@ object MillMain {
       colored = colored,
       enableTicker = enableTicker.getOrElse(true),
       infoColor = colors.info,
+      warnColor = colors.warn,
       errorColor = colors.error,
       systemStreams0 = streams,
       debugEnabled = config.debugLog.value,
diff --git a/testkit/src/mill/testkit/UnitTester.scala b/testkit/src/mill/testkit/UnitTester.scala
index 627c80ba683..0f499db7e79 100644
--- a/testkit/src/mill/testkit/UnitTester.scala
+++ b/testkit/src/mill/testkit/UnitTester.scala
@@ -69,6 +69,7 @@ class UnitTester(
         colored = true,
         enableTicker = false,
         infoColor = mill.internal.Colors.Default.info,
+        warnColor = mill.internal.Colors.Default.warn,
         errorColor = mill.internal.Colors.Default.error,
         systemStreams0 = new SystemStreams(out = outStream, err = errStream, in = inStream),
         debugEnabled = debugEnabled,
@@ -82,6 +83,7 @@ class UnitTester(
       else fullName.value
     }
     override def error(s: String): Unit = super.error(s"${prefix}: ${s}")
+    override def warn(s: String): Unit = super.warn(s"${prefix}: ${s}")
     override def info(s: String): Unit = super.info(s"${prefix}: ${s}")
     override def debug(s: String): Unit = super.debug(s"${prefix}: ${s}")
     override def ticker(s: String): Unit = super.ticker(s"${prefix}: ${s}")