diff --git a/omeroweb/webgateway/views.py b/omeroweb/webgateway/views.py
index 159cd46fba..df860ccee6 100644
--- a/omeroweb/webgateway/views.py
+++ b/omeroweb/webgateway/views.py
@@ -2148,7 +2148,7 @@ def luts_png(request, conn=None, **kwargs):
 
         if len(lut_data) in [768, 800]:
             lut_arr = numpy.array(lut_data, dtype="uint8")[-768:]
-            new_img[(i*10): (i+1)*10, :, :3] = lut_arr.reshape(3, 256).T
+            new_img[(i * 10) : (i + 1) * 10, :, :3] = lut_arr.reshape(3, 256).T
         else:
             lut_data = lut_data.decode()
             r, g, b = [], [], []
@@ -2164,9 +2164,9 @@ def luts_png(request, conn=None, **kwargs):
                 r.append(int(val[-3]))
                 g.append(int(val[-2]))
                 b.append(int(val[-1]))
-            new_img[(i*10): (i+1)*10, :, 0] = numpy.array(r)
-            new_img[(i*10): (i+1)*10, :, 1] = numpy.array(g)
-            new_img[(i*10): (i+1)*10, :, 2] = numpy.array(b)
+            new_img[(i * 10) : (i + 1) * 10, :, 0] = numpy.array(r)
+            new_img[(i * 10) : (i + 1) * 10, :, 1] = numpy.array(g)
+            new_img[(i * 10) : (i + 1) * 10, :, 2] = numpy.array(b)
 
     # Set the last row for the channel sliders transparent gradient
     new_img[-10:] = 0