diff --git a/src/main.rs b/src/main.rs
index 6b75bfa..d4f97a4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -27,6 +27,9 @@ struct Cli {
     rows: usize,
     /// Free-format arguments to pass to the executable
     args: Vec<String>,
+    /// Use RGBW pixel format
+    #[arg(short, long, action = clap::ArgAction::SetTrue)]
+    white: bool,
     /// Frame rate for displaying
     #[arg(short, long, default_value_t = 25)]
     frame_rate: u64,
@@ -76,8 +79,7 @@ fn main() -> Result<(), Box<dyn error::Error>> {
         .take()
         .ok_or("opening app process stdout failed")?;
 
-    // TODO support also RGBW
-    let colors = 3;
+    let colors = if cli.white { 4 } else { 3 };
     // TODO check for overflow and excessive size
     let buffer_size = cli.cols * cli.rows * colors;
     let mut frame_count = 0;
@@ -144,10 +146,23 @@ fn main() -> Result<(), Box<dyn error::Error>> {
                 for y in 0..y_size {
                     for x in 0..x_size {
                         let i = colors * (y * x_size + x);
-                        let r = f32::from(buffer.frame[i + 0]) / 255.0;
-                        let g = f32::from(buffer.frame[i + 1]) / 255.0;
-                        let b = f32::from(buffer.frame[i + 2]) / 255.0;
-                        let color = [r, g, b, 1.0];
+                        let color = if colors == 3 {
+                            let r = f32::from(buffer.frame[i + 0]) / 255.0;
+                            let g = f32::from(buffer.frame[i + 1]) / 255.0;
+                            let b = f32::from(buffer.frame[i + 2]) / 255.0;
+                            [r, g, b, 1.0]
+                        } else {
+                            let r = f32::from(buffer.frame[i + 0]) / 255.0;
+                            let g = f32::from(buffer.frame[i + 1]) / 255.0;
+                            let b = f32::from(buffer.frame[i + 2]) / 255.0;
+                            let w = f32::from(buffer.frame[i + 3]) / 255.0;
+                            [
+                                (0.5 * r + 0.8 * w).min(1.0),
+                                (0.5 * g + 0.7 * w).min(1.0),
+                                (0.5 * b + 0.6 * w).min(1.0),
+                                1.0,
+                            ]
+                        };
                         let rectangle = [(x as f64) * cs, (y as f64) * cs, cs, cs];
                         pw::rectangle(color, rectangle, context.transform, graphics);
                     }