diff --git a/src/util/color_reader.py b/src/util/color_reader.py
index d7a3d61..a5c33ff 100644
--- a/src/util/color_reader.py
+++ b/src/util/color_reader.py
@@ -78,6 +78,14 @@ def str2closest_html_color_name(s: str):
         return ''
 
 
+def rgba2rgb(r, g, b, alpha):
+    r_background, g_background, b_background = 255, 255, 255
+    r_new = int((1 - alpha) * r_background + alpha * r)
+    g_new = int((1 - alpha) * g_background + alpha * g)
+    b_new = int((1 - alpha) * b_background + alpha * b)
+    return r_new, g_new, b_new
+
+
 def str2hex(s: str):
     if '#' in s:
         return s.lower()
@@ -89,20 +97,26 @@ def str2hex(s: str):
             return rgb_percent_to_hex((r, g, b))
 
     if 'rgb' in s:
-        match = re.search(r'rgba*\(((\d+), *(\d+), *(\d+)(, \d\.\d+)*)\)', s)
+        match = re.search(r'rgba*\(((\d+), *(\d+), *(\d+), (\d\.\d+)*)\)', s)
         if match:
             r, g, b = int(match.group(2)), int(match.group(3)), int(match.group(4))
+            if match.group(5):
+                alpha = float(match.group(5))
+                r, g, b = rgba2rgb(r, g, b, alpha)
             return rgb_to_hex((r, g, b))
 
     if 'hsl' in s:
         # hsl(hue in {0,360}, saturation [0, 100%], lightness [0, 100%])
-        match = re.search(r'hsla*\(((\d+), *(\d+)%, *(\d+)%(, \d\.\d+)*)\)', s)
+        match = re.search(r'hsla*\(((\d+), *(\d+)%, *(\d+)%, (\d\.\d+)*)\)', s)
         if match:
             h, s, l = int(match.group(2)), int(match.group(3)), int(match.group(4))
             h /= 360
             s /= 10
             l /= 100
             rgb = tuple(hls_to_rgb(h, s, l))
+            if match.group(5):
+                alpha = match.group(5)
+                rgb = rgba2rgb(*rgb, alpha)
             return rgb_to_hex(rgb)
 
     if s.lower() in css3_names_to_hex: