diff --git a/spateo/plotting/static/utils.py b/spateo/plotting/static/utils.py
index 697f7ee6..9613bc99 100755
--- a/spateo/plotting/static/utils.py
+++ b/spateo/plotting/static/utils.py
@@ -101,17 +101,17 @@ def _to_hex(arr):
 """
 
 
-@numba.vectorize(["uint8(uint32)", "uint8(uint32)"])
+@numba.vectorize(["uint8(uint32)"])
 def _red(x):
     return (x & 0xFF0000) >> 16
 
 
-@numba.vectorize(["uint8(uint32)", "uint8(uint32)"])
+@numba.vectorize(["uint8(uint32)"])
 def _green(x):
     return (x & 0x00FF00) >> 8
 
 
-@numba.vectorize(["uint8(uint32)", "uint8(uint32)"])
+@numba.vectorize(["uint8(uint32)"])
 def _blue(x):
     return x & 0x0000FF