diff --git a/colortest/.gitignore b/colortest/.gitignore
new file mode 100644
index 0000000..eb5a316
--- /dev/null
+++ b/colortest/.gitignore
@@ -0,0 +1 @@
+target
diff --git a/colortest/Cargo.lock b/colortest/Cargo.lock
new file mode 100644
index 0000000..3042db8
--- /dev/null
+++ b/colortest/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "colortest"
+version = "0.1.0"
diff --git a/colortest/Cargo.toml b/colortest/Cargo.toml
new file mode 100644
index 0000000..693afde
--- /dev/null
+++ b/colortest/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "colortest"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/colortest/README.md b/colortest/README.md
new file mode 100644
index 0000000..b5edffc
--- /dev/null
+++ b/colortest/README.md
@@ -0,0 +1 @@
+https://gist.github.com/chadaustin/2d2c2cb4b71fd1d4163aa8115077624a
diff --git a/colortest/src/main.rs b/colortest/src/main.rs
new file mode 100644
index 0000000..b38bd2e
--- /dev/null
+++ b/colortest/src/main.rs
@@ -0,0 +1,209 @@
+#!/usr/bin/env -S rust-script -t nightly
+#![feature(unix_sigpipe)]
+
+use std::cmp::max;
+
+const BASIC_COLORS: &[&str] = &[
+    "black", "red", "green", "yellow", "blue", "magenta", "cyan", "white",
+];
+
+fn title(t: &str) {
+    println!("{}\n{: <2$}", t, "", t.len())
+}
+
+fn reset() {
+    print!("\x1B[m");
+}
+
+fn sgr(p: u32) {
+    print!("\x1B[{}m", p);
+}
+
+fn color_table_with_offset(fg_offset: usize, bg_offset: usize) {
+    for (bg, _) in BASIC_COLORS.iter().enumerate() {
+        print!("\x1B[{}m", bg_offset + bg);
+        for (fg, fg_name) in BASIC_COLORS.iter().enumerate() {
+            print!("\x1B[{}m", fg_offset + fg);
+            print!(" {} ", fg_name);
+        }
+        println!("\x1B[39;49m");
+    }
+}
+
+fn basic_color_table() {
+    color_table_with_offset(30, 40)
+}
+
+fn aix_bright_color_table() {
+    color_table_with_offset(90, 100)
+}
+
+fn fg_index_legacy(i: u32) {
+    print!("\x1B[38;5;{}m", i);
+}
+fn bg_index_legacy(i: u32) {
+    print!("\x1B[48;5;{}m", i);
+}
+fn fg_index_standard(i: u32) {
+    print!("\x1B[38:5:{}m", i);
+}
+fn bg_index_standard(i: u32) {
+    print!("\x1B[48:5:{}m", i);
+}
+fn fg_rgb_legacy(r: u8, g: u8, b: u8) {
+    print!("\x1B[38;2;{};{};{}m", r, g, b);
+}
+fn bg_rgb_legacy(r: u8, g: u8, b: u8) {
+    print!("\x1B[48;2;{};{};{}m", r, g, b);
+}
+fn fg_rgb_standard(r: u8, g: u8, b: u8) {
+    print!("\x1B[38:2::{}:{}:{}m", r, g, b);
+}
+fn bg_rgb_standard(r: u8, g: u8, b: u8) {
+    print!("\x1B[48:2::{}:{}:{}m", r, g, b);
+}
+fn reset_fgbg() {
+    println!("\x1B[39;49m");
+}
+
+fn color_cube(fg_index: fn(u32), bg_index: fn(u32)) {
+    for i in 0..16 {
+        fg_index(16 - i - 1);
+        bg_index(i);
+        print!("x");
+    }
+    reset_fgbg();
+    for i in 0..6 {
+        for j in 0..36 {
+            fg_index(16 + 36 * i + j);
+            bg_index(16 + 216 - (36 * i + j) - 1);
+            print!("x");
+        }
+        reset_fgbg();
+    }
+    for i in 232..256 {
+        fg_index(232 + 256 - i - 1);
+        bg_index(i);
+        print!("x");
+    }
+    reset_fgbg();
+}
+
+fn legacy_color_cube() {
+    color_cube(fg_index_legacy, bg_index_legacy);
+}
+
+fn standard_color_cube() {
+    color_cube(fg_index_standard, bg_index_standard);
+}
+
+fn rgb(fg_rgb: fn(u8, u8, u8), bg_rgb: fn(u8, u8, u8)) {
+    const V: [u8; 17] = [
+        0, 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176, 192, 208, 224, 240, 255,
+    ];
+
+    for i in 0..17 {
+        for j in 0..17 {
+            let r = 255 - V[max(i, j)];
+            let g = V[j];
+            let b = V[i];
+            fg_rgb(255 - r, 255 - g, 255 - b);
+            bg_rgb(r, g, b);
+            print!(" x ");
+        }
+        reset_fgbg();
+    }
+}
+
+fn legacy_rgb() {
+    rgb(fg_rgb_legacy, bg_rgb_legacy);
+}
+
+fn standard_rgb() {
+    rgb(fg_rgb_standard, bg_rgb_standard);
+}
+
+fn other_character_functions() {
+    fn reset_sgr(p: u32) {
+        print!("\x1B[;{}m", p);
+    }
+    // https://invisible-island.net/xterm/ctlseqs/ctlseqs.html#h4-Functions-using-CSI-_-ordered-by-the-final-character-lparen-s-rparen:CSI-Pm-m.1CA7
+    // T-REC-T.416-199303-I!!PDF-E.pdf
+    // https://www.ecma-international.org/wp-content/uploads/ECMA-48_5th_edition_june_1991.pdf
+    const CODES: &[(u32, &str)] = &[
+        (0, "plain"),
+        (1, "bold"),
+        (2, "faint"),
+        (3, "italic"),
+        (4, "underline"),
+        (5, "slow blink"),
+        (6, "fast blink"),
+        (7, "reverse"),
+        (8, "conceal"),
+        (9, "crossed out"),
+        (21, "double underline?"),
+        (51, "framed"),
+        (52, "encircled"),
+        (53, "overlined"),
+        // Ideogram parameters:
+    ];
+    let mut i = 0;
+    for (code, name) in CODES {
+        if i >= 8 {
+            println!();
+            i = 0;
+        }
+        i += 1;
+
+        print!("{}: ", code);
+        reset_sgr(*code);
+        print!("{}", name);
+        sgr(0);
+        print!("  ");
+    }
+    println!();
+}
+
+#[unix_sigpipe = "inherit"]
+fn main() {
+    title("ANSI basic colors");
+
+    basic_color_table();
+    reset();
+
+    println!();
+    title("ANSI bold/bright basic colors");
+    print!("\x1B[{}m", 1);
+    basic_color_table();
+    reset();
+
+    println!();
+    title("AIX (nonstandard) bright colors");
+    aix_bright_color_table();
+    reset();
+
+    println!();
+    title("256-color palette (legacy semicolon syntax)");
+    legacy_color_cube();
+    reset();
+
+    println!();
+    title("256-color palette (standard colon syntax)");
+    standard_color_cube();
+    reset();
+
+    println!();
+    title("24-bit RGB (legacy semicolon syntax)");
+    legacy_rgb();
+    reset();
+
+    println!();
+    title("24-bit RGB (standard colon syntax)");
+    standard_rgb();
+    reset();
+
+    println!();
+    title("Other character functions");
+    other_character_functions();
+    reset();
+}