diff --git a/lib/system/supports-colors.js b/lib/system/supports-colors.js
index d2b02a3..48509a6 100644
--- a/lib/system/supports-colors.js
+++ b/lib/system/supports-colors.js
@@ -24,27 +24,9 @@ THE SOFTWARE.
 */
 
 'use strict';
-var os = require('os');
 var hasFlag = require('./has-flag.js');
 
-var env = process.env;
-
-var forceColor;
-if (hasFlag('no-color') ||
-	hasFlag('no-colors') ||
-	hasFlag('color=false')) {
-	forceColor = false;
-} else if (hasFlag('color') ||
-	hasFlag('colors') ||
-	hasFlag('color=true') ||
-	hasFlag('color=always')) {
-	forceColor = true;
-}
-if ('FORCE_COLOR' in env) {
-	forceColor = env.FORCE_COLOR.length === 0 || parseInt(env.FORCE_COLOR, 10) !== 0;
-}
-
-function translateLevel(level) {
+var support = function (level) {
 	if (level === 0) {
 		return false;
 	}
@@ -55,10 +37,12 @@ function translateLevel(level) {
 		has256: level >= 2,
 		has16m: level >= 3
 	};
-}
+};
 
-function supportsColor(stream) {
-	if (forceColor === false) {
+var supportLevel = (function () {
+	if (hasFlag('no-color') ||
+		hasFlag('no-colors') ||
+		hasFlag('color=false')) {
 		return 0;
 	}
 
@@ -72,83 +56,42 @@ function supportsColor(stream) {
 		return 2;
 	}
 
-	if (stream && !stream.isTTY && forceColor !== true) {
+	if (hasFlag('color') ||
+		hasFlag('colors') ||
+		hasFlag('color=true') ||
+		hasFlag('color=always')) {
+		return 1;
+	}
+
+	if (process.stdout && !process.stdout.isTTY) {
 		return 0;
 	}
 
-	var min = forceColor ? 1 : 0;
-
 	if (process.platform === 'win32') {
-		// Node.js 7.5.0 is the first version of Node.js to include a patch to
-		// libuv that enables 256 color output on Windows. Anything earlier and it
-		// won't work. However, here we target Node.js 8 at minimum as it is an LTS
-		// release, and Node.js 7 is not. Windows 10 build 10586 is the first Windows
-		// release that supports 256 colors. Windows 10 build 14931 is the first release
-		// that supports 16m/TrueColor.
-		var osRelease = os.release().split('.');
-		if (
-			Number(process.versions.node.split('.')[0]) >= 8 &&
-			Number(osRelease[0]) >= 10 &&
-			Number(osRelease[2]) >= 10586
-		) {
-			return Number(osRelease[2]) >= 14931 ? 3 : 2;
-		}
-
 		return 1;
 	}
 
-	if ('CI' in env) {
-		if (['TRAVIS', 'CIRCLECI', 'APPVEYOR', 'GITLAB_CI'].some(sign => sign in env) || env.CI_NAME === 'codeship') {
-			return 1;
-		}
-
-		return min;
+	if ('COLORTERM' in process.env) {
+		return 1;
 	}
 
-	if ('TEAMCITY_VERSION' in env) {
-		return /^(9\.(0*[1-9]\d*)\.|\d{2,}\.)/.test(env.TEAMCITY_VERSION) ? 1 : 0;
+	if (process.env.TERM === 'dumb') {
+		return 0;
 	}
 
-	if ('TERM_PROGRAM' in env) {
-		var version = parseInt((env.TERM_PROGRAM_VERSION || '').split('.')[0], 10);
-
-		switch (env.TERM_PROGRAM) {
-			case 'iTerm.app':
-				return version >= 3 ? 3 : 2;
-			case 'Hyper':
-				return 3;
-			case 'Apple_Terminal':
-				return 2;
-			// No default
-		}
-	}
-
-	if (/-256(color)?$/i.test(env.TERM)) {
+	if (/^xterm-256(?:color)?/.test(process.env.TERM)) {
 		return 2;
 	}
 
-	if (/^screen|^xterm|^vt100|^rxvt|color|ansi|cygwin|linux/i.test(env.TERM)) {
+	if (/^screen|^xterm|^vt100|color|ansi|cygwin|linux/i.test(process.env.TERM)) {
 		return 1;
 	}
 
-	if ('COLORTERM' in env) {
-		return 1;
-	}
+	return 0;
+})();
 
-	if (env.TERM === 'dumb') {
-		return min;
-	}
-
-	return min;
+if (supportLevel === 0 && 'FORCE_COLOR' in process.env) {
+	supportLevel = 1;
 }
 
-function getSupportLevel(stream) {
-	var level = supportsColor(stream);
-	return translateLevel(level);
-}
-
-module.exports = {
-	supportsColor: getSupportLevel,
-	stdout: getSupportLevel(process.stdout),
-	stderr: getSupportLevel(process.stderr)
-};
+module.exports = process && support(supportLevel);