diff --git a/js/lib/color_utils.js b/js/lib/color_utils.js
index 74cff36..1ed5a65 100644
--- a/js/lib/color_utils.js
+++ b/js/lib/color_utils.js
@@ -113,6 +113,13 @@ function pad (n) {
   return n
 }
 
+exports.rgb255_to_hex = function (r, g, b) {
+  r = r.toString(16)
+  g = g.toString(16)
+  b = b.toString(16)
+  return `#${pad(r)}${pad(g)}${pad(b)}`
+}
+
 exports.rgb_to_hex = function (r, g, b) {
   r = Math.round(r * 255).toString(16)
   g = Math.round(g * 255).toString(16)
diff --git a/js/term/themes.js b/js/term/themes.js
index aa93bc1..a1b84ee 100644
--- a/js/term/themes.js
+++ b/js/term/themes.js
@@ -1,5 +1,5 @@
 const $ = require('../lib/chibi')
-const { rgb_to_hex } = require('../lib/color_utils')
+const { rgb255_to_hex } = require('../lib/color_utils')
 
 const themes = exports.themes = [
   [ // 0 - Tango - terminator
@@ -84,14 +84,14 @@ exports.buildColorTable = function () {
         let redValue = red * 40 + (red ? 55 : 0)
         let greenValue = green * 40 + (green ? 55 : 0)
         let blueValue = blue * 40 + (blue ? 55 : 0)
-        colorTable256.push(rgb_to_hex(redValue, greenValue, blueValue))
+        colorTable256.push(rgb255_to_hex(redValue, greenValue, blueValue))
       }
     }
   }
   // colors 232-255 are a grayscale ramp, sans black and white
   for (let gray = 0; gray < 24; gray++) {
     let value = gray * 10 + 8
-    colorTable256.push(rgb_to_hex(value, value, value))
+    colorTable256.push(rgb255_to_hex(value, value, value))
   }
 
   return colorTable256