diff -r baa33d32308e -r ca10547ba9db qmsk/dmx/web.py
--- a/qmsk/dmx/web.py	Fri Apr 11 21:45:26 2014 +0300
+++ b/qmsk/dmx/web.py	Fri Apr 11 22:22:11 2014 +0300
@@ -39,23 +39,27 @@
     TITLE = u"Hello World"
 
     def process (self) :
-        self.color = (
-                self.request.form.get('r'),
-                self.request.form.get('g'),
-                self.request.form.get('b'),
-        )
+        if self.request.method == 'POST' :
+            self.color = tuple((int(x, 16) if x else 0) for x in (
+                    self.request.form.get('r'),
+                    self.request.form.get('g'),
+                    self.request.form.get('b'),
+            ))
 
-        self.color = tuple((int(x, 16) if x else None) for x in self.color)
-
-        if self.request.method == 'POST' :
             r, g, b = self.color
 
             self.app.dmx_color(r, g, b, 255)
 
+        else :
+            self.color = None
+
         log.info("%s", self.color)
 
     def render (self) :
-        r, g, b = self.color
+        if self.color :
+            r, g, b = self.color
+        else :
+            r = g = b = None
 
         def color_input (name, value) :
             color = dict(r=0, g=0, b=0)
@@ -63,12 +67,16 @@
 
             if value :
                 color[name] = value
+                alpha = value / 2
+            else :
+                alpha = 0
+
             bgcolor[name] = 255
 
             return html.input(type='text', name=name, class_='form-control', placeholder=name,
-                    value   = '{:02x}'.format(value),
+                    value   = '{v:02x}'.format(v=value) if value else None,
                     #style   = 'background-color: #{r:02x}{g:02x}{b:02x}'.format(**color),
-                    style   = 'background-color: rgba({r}, {g}, {b}, {a})'.format(a=value, **bgcolor),
+                    style   = 'background-color: rgba({r}, {g}, {b}, {a})'.format(a=alpha, **bgcolor),
             )
 
         return html.div(class_='container')(
@@ -99,6 +107,7 @@
 
     def dmx_color (self, r, g, b, a=255) :
         for c in (1, 30) :
+            # XXX: this is four separate commands... each one flushes...
             self.dmx[c + 0:c + 26:3] = r
             self.dmx[c + 1:c + 26:3] = g
             self.dmx[c + 2:c + 26:3] = b