diff --git a/environment.yml b/environment.yml
index 1f49368..d772ac7 100644
--- a/environment.yml
+++ b/environment.yml
@@ -12,6 +12,7 @@ dependencies:
   - jupyterlab-myst
   - jupyter-book
   - notebook
+  - postgresql
   - cellpose
   - coin-or-cbc
   - gurobi
diff --git a/tutorial/color_tracking.md b/tutorial/color_tracking.md
index e4bc54e..809e41a 100644
--- a/tutorial/color_tracking.md
+++ b/tutorial/color_tracking.md
@@ -59,7 +59,6 @@ def screenshot() -> None:
 We will load the data and display in the viewer as an RGB image.
 
 ```{code-cell} ipython3
-
 image = imread("multi-color-cytoplasm.tif")
 print("Image array shape", image.shape)
 
@@ -71,4 +70,4 @@ screenshot()
 The image stack have 3 channels, since we don't have multi-color segmentation model (or at least I don't), we could process each channel individually and then combine them using Ultrack's to obtain a final segmentation and tracking without complicated heuristics for multi-color tracking.
 ```
 
-## Your turn!
\ No newline at end of file
+## Your turn!