diff --git a/libs/microbit/basic.ts b/libs/microbit/basic.ts
new file mode 100644
index 00000000..63dfdf4f
--- /dev/null
+++ b/libs/microbit/basic.ts
@@ -0,0 +1,56 @@
+/**
+  Well known colors
+*/
+enum Colors {
+    //% blockIdentity=basic.color
+    //% block=red
+    Red = 0xFF0000,
+    //% blockIdentity=basic.color
+    //% block=orange
+    Orange = 0xFFA500,
+    //% blockIdentity=basic.color
+    //% block=yellow
+    Yellow = 0xFFFF00,
+    //% blockIdentity=basic.color
+    //% block=green
+    Green = 0x00FF00,
+    //% blockIdentity=basic.color
+    //% block=blue
+    Blue = 0x0000FF,
+    //% blockIdentity=basic.color
+    //% block=indigo
+    Indigo = 0x4b0082,
+    //% blockIdentity=basic.color
+    //% block=violet
+    Violet = 0x8a2be2,
+    //% blockIdentity=basic.color
+    //% block=purple
+    Purple = 0xFF00FF,
+    //% blockIdentity=basic.color
+    //% block=white
+    White = 0xFFFFFF
+}
+
+/**
+ * Provides access to basic micro:bit functionality.
+ */
+//% color=#0078D7 weight=100
+namespace basic {
+
+    /**
+    * Sets the color on the build-in LED
+    */
+    //% blockId=device_set_led_color block="set led to %color=color_id" icon="\uf00a"
+    //% weight=50
+    export function setLedColor(color: number) {
+        // TODO
+    }
+
+    /**
+     * Converts the color name to a number
+     */
+    //% blockId=color_id block="%c" shim=TD_ID
+    export function color(c: Colors): number {
+        return c;
+    }
+}
\ No newline at end of file
diff --git a/libs/microbit/pxt.json b/libs/microbit/pxt.json
index be53b812..34847ae0 100644
--- a/libs/microbit/pxt.json
+++ b/libs/microbit/pxt.json
@@ -14,6 +14,7 @@
         "helpers.ts",
         "images.cpp",
         "basic.cpp",
+        "basic.ts",
         "input.cpp",
         "input.ts",
         "control.ts",
diff --git a/sim/dalboard.ts b/sim/dalboard.ts
index b888a7bc..61cb1157 100644
--- a/sim/dalboard.ts
+++ b/sim/dalboard.ts
@@ -13,6 +13,7 @@ namespace pxsim {
         buttonPairState: ButtonPairState;
         radioState: RadioState;
         neopixelState: NeoPixelState;
+        rgbLedState: number;
 
         constructor() {
             super()
@@ -48,7 +49,7 @@ namespace pxsim {
                     0,
                     0,
                     DAL.MICROBIT_ID_IO_P19,
-                    DAL.MICROBIT_ID_IO_P20                    
+                    DAL.MICROBIT_ID_IO_P20
                 ]
             });
             this.builtinParts["radio"] = this.radioState = new RadioState(runtime);
@@ -61,11 +62,11 @@ namespace pxsim {
 
             this.builtinVisuals["buttonpair"] = () => new visuals.ButtonPairView();
             this.builtinVisuals["ledmatrix"] = () => new visuals.LedMatrixView();
-            this.builtinVisuals["neopixel"] = () => new visuals.NeoPixelView();            
+            this.builtinVisuals["neopixel"] = () => new visuals.NeoPixelView();
 
             this.builtinPartVisuals["buttonpair"] = (xy: visuals.Coord) => visuals.mkBtnSvg(xy);
             this.builtinPartVisuals["ledmatrix"] = (xy: visuals.Coord) => visuals.mkLedMatrixSvg(xy, 8, 8);
-            this.builtinPartVisuals["neopixel"] = (xy: visuals.Coord) => visuals.mkNeoPixelPart(xy);            
+            this.builtinPartVisuals["neopixel"] = (xy: visuals.Coord) => visuals.mkNeoPixelPart(xy);
         }
 
         receiveMessage(msg: SimulatorMessage) {
@@ -97,7 +98,7 @@ namespace pxsim {
             const cmpDefs = msg.partDefinitions || {};
             const fnArgs = msg.fnArgs;
 
-            const opts : visuals.BoardHostOpts = {
+            const opts: visuals.BoardHostOpts = {
                 state: this,
                 boardDef: boardDef,
                 partsList: cmpsList,
diff --git a/sim/state/rgbled.ts b/sim/state/rgbled.ts
new file mode 100644
index 00000000..bb88b0f5
--- /dev/null
+++ b/sim/state/rgbled.ts
@@ -0,0 +1,5 @@
+namespace pxsim.basic {
+    export function setLedColor(c: number) {
+        board().rgbLedState = c;
+    }
+}
\ No newline at end of file
diff --git a/sim/visuals/microbit.ts b/sim/visuals/microbit.ts
index 166617ff..94f9e05c 100644
--- a/sim/visuals/microbit.ts
+++ b/sim/visuals/microbit.ts
@@ -253,6 +253,7 @@ namespace pxsim.visuals {
         private shakeButton: SVGElement;
         public board: pxsim.DalBoard;
         private pinNmToCoord: Map<Coord> = {};
+        private rgbLed: SVGElement;
 
         constructor(public props: IBoardProps) {
             this.recordPinCoords();
@@ -341,11 +342,21 @@ namespace pxsim.visuals {
             this.updateTemperature();
             this.updateButtonAB();
             this.updateGestures();
+            this.updateRgbLed();
 
             if (!runtime || runtime.dead) svg.addClass(this.element, "grayscale");
             else svg.removeClass(this.element, "grayscale");
         }
 
+        private updateRgbLed() {
+            let state = this.board;
+            if (state.rgbLedState) {
+                if (!this.rgbLed)
+                    this.rgbLed = svg.child(this.g, "circle", { cx: 170, cy: 200 });
+                svg.fill(this.rgbLed, svg.toHtmlColor(state.rgbLedState));
+            }
+        }
+
         private updateGestures() {
             let state = this.board;
             if (state.accelerometerState.useShake && !this.shakeButton) {
@@ -353,7 +364,7 @@ namespace pxsim.visuals {
                 this.shakeButton = shake.inner;
                 svg.fill(this.shakeButton, this.props.theme.virtualButtonUp)
                 svg.buttonEvents(shake.outer,
-                    ev => {},
+                    ev => { },
                     (ev) => {
                         svg.fill(this.shakeButton, this.props.theme.virtualButtonDown)
                     },