diff --git a/colorbar-fastloop.py b/colorbar-fastloop.py
index 0f3e3b8..a140d49 100644
--- a/colorbar-fastloop.py
+++ b/colorbar-fastloop.py
@@ -15,7 +15,7 @@ brightness = 0.1
 pixels = neopixel.NeoPixel(
         pixel_pin,
         num_pixels,
-        brightness = brightness,
+        brightness=brightness,
         auto_write=False,
         pixel_order="GRBW"
         )
@@ -34,6 +34,37 @@ pixels.show()
 # END Neopixel setup
 ####
 
+# Set the color on a single neopixel based on colormode and
+#   whether yellowtime or redtime has been reached. Calling
+#   logic should iterate over every neopixel ID that should
+#   be updated during the current update interval, and then
+#   call pixels.show() after all pixels have been set. It's
+#   up to the calling logic to calculate whether the yellow
+#   or red parameters should be set to True. Behavior when
+#   red and yellow are both set to True depends on how the
+#   colormode is configured.
+def colorizer(pxnum, colormode, yellow=False, red=False):
+    # Every pixel from lowest to currently highest
+    if colormode == "fill":
+        if red:
+            pixels[pxnum] = RED
+        elif yellow:
+            pixels[pxnum] = YELLOW
+        else:
+            pixels[pxnum] = GREEN
+    elif colormode == "candybar":
+        if pixels[pxnum] == BLANK:
+            if red:
+                pixels[pxnum] = RED
+            elif yellow:
+                pixels[pxnum] = YELLOW
+            else:
+                pixels[pxnum] = GREEN
+        else:
+            pass
+    else:
+        # Invalid colormodes end up here
+        raise Exception("Invalid colormode: " + colormode)
 
 # Count down from the given total seconds, using the chosen
 #   colormode (how the colors are filled into each pixel),
@@ -41,7 +72,12 @@ pixels.show()
 #   that the bar should show yellow), and redtime (same as
 #   yellowtime). The colormode determines what happens at
 #   yellowtime and redtime.
-def countdown(seconds, colormode="fill", yellowtime=120, redtime=60, update_interval=1):
+def countdown(
+        seconds,
+        colormode="fill",
+        yellowtime=120,
+        redtime=60,
+        update_interval=1):
 
     # Turn all pixels off
     pixels.fill(BLANK)
@@ -53,10 +89,16 @@ def countdown(seconds, colormode="fill", yellowtime=120, redtime=60, update_inte
     # Init the elapsed time variable
     elapsed_time = 0
 
-    # Pre-calculate rtime and ytime
-    rtime = seconds - redtime
-    ytime = seconds - yellowtime
-
+    # This begins what I like to call the "Are We There Yet?"
+    #   loop. Instead of making the script wait for an interval
+    #   before continuing as a form of forced timed pacing, we
+    #   simply write an infinite loop that will iterate very
+    #   quickly between update intervals, essentially repeatedly
+    #   asking the CPU to calculate whether it's time to do an
+    #   update yet. The high frequency of the update interval
+    #   checks will make sure our update is fired on-time.
+    #
+    # ...unless we decide to configure a way to kill the loop entirely, I guess...? ;)
     while True:
         # Get the current time
         now = time.monotonic()
@@ -64,13 +106,21 @@ def countdown(seconds, colormode="fill", yellowtime=120, redtime=60, update_inte
         # Is it time for an update yet?
         if now >= last_update_time + update_interval:
 
-            # d the last update time
+            # Update the last update time
             last_update_time = now
 
             # Do update stuff
+
+            # Loop over every pixel ID that should be lit
+            #   based on the elapsed time
             for pixel in range(round(num_pixels * (elapsed_time / seconds))):
                 # Set pixel color stuff
-                pass
+                if elapsed_time >= seconds - redtime:
+                    colorizer(pixel, colormode, red=True)
+                elif elapsed_time >= seconds - yellowtime:
+                    colorizer(pixel, colormode, yellow=True)
+                else:
+                    colorizer(pixel, colormode)
 
             # Display the result IRL
             pixels.show()