Ok maybe this hack works instead t

ImageColorizerColab.ipynb

@@ -117,7 +117,7 @@
    },
    "outputs": [],
    "source": [
-    "!pip install -r requirements.txt"
+    "!pip install -r colab_requirements.txt"
    ]
   },
   {

VideoColorizerColab.ipynb

@@ -118,7 +118,7 @@
    },
    "outputs": [],
    "source": [
-    "!pip install -r requirements.txt"
+    "!pip install -r colab_requirements.txt"
    ]
   },
   {

colab_requirements.txt

@@ -0,0 +1,8 @@
+fastai==1.0.51
+tensorboardX==1.6
+ffmpeg
+ffmpeg-python==0.1.17
+youtube-dl>=2019.4.17
+jupyterlab
+opencv-python>=3.3.0.10
+pillow

requirements.txt

@@ -5,4 +5,4 @@ ffmpeg-python==0.1.17
 youtube-dl>=2019.4.17
 jupyterlab
 opencv-python>=3.3.0.10
-pillow==5.3.0
+pillow==6.2.2