diff --git a/cmake/doc/cmake.dot b/cmake/doc/cmake.dot
index 0db4ee00ff..135f99fec5 100644
--- a/cmake/doc/cmake.dot
+++ b/cmake/doc/cmake.dot
@@ -1,8 +1,7 @@
 // C++: royalblue
 // Python: gold
 // Java: crimson
-// .Net: forestgreen
-// F#: indigo
+// .Net: darkviolet
 @startdot
 digraph CMake {
   //rankdir=BT;
@@ -14,8 +13,8 @@ digraph CMake {
     SWIG [label="Swig\n(Unix)", fillcolor=chocolate];
     PY [label="Python\n(3.5+)", fillcolor=gold];
     JV [label="Java\n(openJDK 8+)", fillcolor=crimson];
-    DN [label=".Net Core SDK\n(3.0.101)", fillcolor=forestgreen];
-    FS [label=".Net F#", fillcolor=forestgreen];
+    DN [label=".Net Core SDK\n(3.0.101)", fillcolor=darkviolet];
+    FS [label=".Net F#", fillcolor=darkviolet];
     CM -> SWIG [arrowhead=none, style=invisible];
     SWIG -> PY [arrowhead=none, style=invisible];
     SWIG -> JV [arrowhead=none, style=invisible];
@@ -219,7 +218,7 @@ digraph CMake {
     } // clusterJava
 
     subgraph clusterNet {
-      node [shape=box, style="rounded,filled", color=black, fillcolor=forestgreen];
+      node [shape=box, style="rounded,filled", color=black, fillcolor=darkviolet];
       OR_WNET [label="C++ .Net wrappers", shape=note];
       OR_NET [label=".Net files", shape=note];
       PKG_NET_RT [label="Nuget runtime package\nGoogle.OrTools.runtime.rid.nupkg", shape=box3d];
@@ -235,11 +234,11 @@ digraph CMake {
       OR_SRC -> OR_WNET [label="swig", color=chocolate];
       OR_SRC -> OR_NET [label="swig", color=chocolate];
       OR_WNET -> OR_NET;
-      OR_WNET -> PKG_NET_RT [label="dotnet package", color=forestgreen];
-      PKG_NET_RT -> PKG_NET [color=forestgreen];
-      OR_NET -> PKG_NET [label="dotnet package", color=forestgreen];
+      OR_WNET -> PKG_NET_RT [label="dotnet package", color=darkviolet];
+      PKG_NET_RT -> PKG_NET [color=darkviolet];
+      OR_NET -> PKG_NET [label="dotnet package", color=darkviolet];
 
-      color=forestgreen;
+      color=darkviolet;
       label = ".Net\n(-DBUILD_DOTNET=ON)";
     } // clusterNet
 
diff --git a/cmake/doc/cmake.svg b/cmake/doc/cmake.svg
index 1aed5fb9a6..175b8bb196 100644
--- a/cmake/doc/cmake.svg
+++ b/cmake/doc/cmake.svg
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
  "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
-<!-- Generated by graphviz version 2.42.3 (0)
+<!-- Generated by graphviz version 2.44.1 (0)
  -->
 <!-- Title: CMake Pages: 1 -->
 <svg width="1514pt" height="1338pt"
@@ -119,7 +119,7 @@
 </g>
 <g id="clust21" class="cluster">
 <title>clusterNet</title>
-<polygon fill="none" stroke="forestgreen" points="1114,-16 1114,-441 1490,-441 1490,-16 1114,-16"/>
+<polygon fill="none" stroke="darkviolet" points="1114,-16 1114,-441 1490,-441 1490,-16 1114,-16"/>
 <text text-anchor="middle" x="1302" y="-425.8" font-family="Times,serif" font-size="14.00">.Net</text>
 <text text-anchor="middle" x="1302" y="-410.8" font-family="Times,serif" font-size="14.00">(&#45;DBUILD_DOTNET=ON)</text>
 </g>
@@ -183,7 +183,7 @@
 <!-- DN -->
 <g id="node5" class="node">
 <title>DN</title>
-<polygon fill="forestgreen" stroke="black" points="356,-979 238,-979 234,-975 234,-941 352,-941 356,-945 356,-979"/>
+<polygon fill="darkviolet" stroke="black" points="356,-979 238,-979 234,-975 234,-941 352,-941 356,-945 356,-979"/>
 <polyline fill="none" stroke="black" points="352,-975 234,-975 "/>
 <polyline fill="none" stroke="black" points="352,-975 352,-941 "/>
 <polyline fill="none" stroke="black" points="352,-975 356,-979 "/>
@@ -197,7 +197,7 @@
 <!-- FS -->
 <g id="node6" class="node">
 <title>FS</title>
-<polygon fill="forestgreen" stroke="black" points="332,-904 262,-904 258,-900 258,-868 328,-868 332,-872 332,-904"/>
+<polygon fill="darkviolet" stroke="black" points="332,-904 262,-904 258,-900 258,-868 328,-868 332,-872 332,-904"/>
 <polyline fill="none" stroke="black" points="328,-900 258,-900 "/>
 <polyline fill="none" stroke="black" points="328,-900 328,-868 "/>
 <polyline fill="none" stroke="black" points="328,-900 332,-904 "/>
@@ -548,7 +548,7 @@
 <!-- OR_WNET -->
 <g id="node34" class="node">
 <title>OR_WNET</title>
-<polygon fill="forestgreen" stroke="black" points="1276,-395 1124,-395 1124,-359 1282,-359 1282,-389 1276,-395"/>
+<polygon fill="darkviolet" stroke="black" points="1276,-395 1124,-395 1124,-359 1282,-359 1282,-389 1276,-395"/>
 <polyline fill="none" stroke="black" points="1276,-395 1276,-389 "/>
 <polyline fill="none" stroke="black" points="1282,-389 1276,-389 "/>
 <text text-anchor="middle" x="1203" y="-373.3" font-family="Times,serif" font-size="14.00">C++ .Net wrappers</text>
@@ -563,7 +563,7 @@
 <!-- OR_NET -->
 <g id="node35" class="node">
 <title>OR_NET</title>
-<polygon fill="forestgreen" stroke="black" points="1197.5,-307 1122.5,-307 1122.5,-271 1203.5,-271 1203.5,-301 1197.5,-307"/>
+<polygon fill="darkviolet" stroke="black" points="1197.5,-307 1122.5,-307 1122.5,-271 1203.5,-271 1203.5,-301 1197.5,-307"/>
 <polyline fill="none" stroke="black" points="1197.5,-307 1197.5,-301 "/>
 <polyline fill="none" stroke="black" points="1203.5,-301 1197.5,-301 "/>
 <text text-anchor="middle" x="1163" y="-285.3" font-family="Times,serif" font-size="14.00">.Net files</text>
@@ -680,7 +680,7 @@
 <!-- PKG_NET_RT -->
 <g id="node36" class="node">
 <title>PKG_NET_RT</title>
-<polygon fill="forestgreen" stroke="black" points="1482,-308 1226,-308 1222,-304 1222,-270 1478,-270 1482,-274 1482,-308"/>
+<polygon fill="darkviolet" stroke="black" points="1482,-308 1226,-308 1222,-304 1222,-270 1478,-270 1482,-274 1482,-308"/>
 <polyline fill="none" stroke="black" points="1478,-304 1222,-304 "/>
 <polyline fill="none" stroke="black" points="1478,-304 1478,-270 "/>
 <polyline fill="none" stroke="black" points="1478,-304 1482,-308 "/>
@@ -690,14 +690,14 @@
 <!-- OR_WNET&#45;&gt;PKG_NET_RT -->
 <g id="edge51" class="edge">
 <title>OR_WNET&#45;&gt;PKG_NET_RT</title>
-<path fill="none" stroke="forestgreen" d="M1232.79,-358.8C1255.49,-345.71 1286.96,-327.54 1311.87,-313.17"/>
-<polygon fill="forestgreen" stroke="forestgreen" points="1313.81,-316.09 1320.72,-308.06 1310.31,-310.02 1313.81,-316.09"/>
+<path fill="none" stroke="darkviolet" d="M1232.79,-358.8C1255.49,-345.71 1286.96,-327.54 1311.87,-313.17"/>
+<polygon fill="darkviolet" stroke="darkviolet" points="1313.81,-316.09 1320.72,-308.06 1310.31,-310.02 1313.81,-316.09"/>
 <text text-anchor="middle" x="1341" y="-329.8" font-family="Times,serif" font-size="14.00">dotnet package</text>
 </g>
 <!-- PKG_NET -->
 <g id="node37" class="node">
 <title>PKG_NET</title>
-<polygon fill="forestgreen" stroke="black" points="1349,-184 1179,-184 1175,-180 1175,-146 1345,-146 1349,-150 1349,-184"/>
+<polygon fill="darkviolet" stroke="black" points="1349,-184 1179,-184 1175,-180 1175,-146 1345,-146 1349,-150 1349,-184"/>
 <polyline fill="none" stroke="black" points="1345,-180 1175,-180 "/>
 <polyline fill="none" stroke="black" points="1345,-180 1345,-146 "/>
 <polyline fill="none" stroke="black" points="1345,-180 1349,-184 "/>
@@ -707,20 +707,20 @@
 <!-- OR_NET&#45;&gt;PKG_NET -->
 <g id="edge53" class="edge">
 <title>OR_NET&#45;&gt;PKG_NET</title>
-<path fill="none" stroke="forestgreen" d="M1175.38,-270.78C1182.67,-260.78 1192.17,-248.03 1201,-237 1213.2,-221.77 1227.37,-205.2 1238.99,-191.91"/>
-<polygon fill="forestgreen" stroke="forestgreen" points="1241.88,-193.92 1245.85,-184.09 1236.62,-189.3 1241.88,-193.92"/>
+<path fill="none" stroke="darkviolet" d="M1175.38,-270.78C1182.67,-260.78 1192.17,-248.03 1201,-237 1213.2,-221.77 1227.37,-205.2 1238.99,-191.91"/>
+<polygon fill="darkviolet" stroke="darkviolet" points="1241.88,-193.92 1245.85,-184.09 1236.62,-189.3 1241.88,-193.92"/>
 <text text-anchor="middle" x="1256" y="-240.8" font-family="Times,serif" font-size="14.00">dotnet package</text>
 </g>
 <!-- PKG_NET_RT&#45;&gt;PKG_NET -->
 <g id="edge52" class="edge">
 <title>PKG_NET_RT&#45;&gt;PKG_NET</title>
-<path fill="none" stroke="forestgreen" d="M1338.72,-270C1323.57,-249.46 1298.64,-215.67 1281.33,-192.21"/>
-<polygon fill="forestgreen" stroke="forestgreen" points="1284.09,-190.04 1275.33,-184.08 1278.45,-194.2 1284.09,-190.04"/>
+<path fill="none" stroke="darkviolet" d="M1338.72,-270C1323.57,-249.46 1298.64,-215.67 1281.33,-192.21"/>
+<polygon fill="darkviolet" stroke="darkviolet" points="1284.09,-190.04 1275.33,-184.08 1278.45,-194.2 1284.09,-190.04"/>
 </g>
 <!-- EX_NET -->
 <g id="node38" class="node">
 <title>EX_NET</title>
-<path fill="forestgreen" stroke="black" d="M1305,-68C1305,-68 1219,-68 1219,-68 1213,-68 1207,-62 1207,-56 1207,-56 1207,-44 1207,-44 1207,-38 1213,-32 1219,-32 1219,-32 1305,-32 1305,-32 1311,-32 1317,-38 1317,-44 1317,-44 1317,-56 1317,-56 1317,-62 1311,-68 1305,-68"/>
+<path fill="darkviolet" stroke="black" d="M1305,-68C1305,-68 1219,-68 1219,-68 1213,-68 1207,-62 1207,-56 1207,-56 1207,-44 1207,-44 1207,-38 1213,-32 1219,-32 1219,-32 1305,-32 1305,-32 1311,-32 1317,-38 1317,-44 1317,-44 1317,-56 1317,-56 1317,-62 1311,-68 1305,-68"/>
 <text text-anchor="middle" x="1262" y="-46.3" font-family="Times,serif" font-size="14.00">.Net samples</text>
 </g>
 <!-- PKG_NET&#45;&gt;EX_NET -->
diff --git a/cmake/doc/deps.svg b/cmake/doc/deps.svg
index 290f427d27..652ebcbc52 100644
--- a/cmake/doc/deps.svg
+++ b/cmake/doc/deps.svg
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
  "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
-<!-- Generated by graphviz version 2.42.3 (0)
+<!-- Generated by graphviz version 2.44.1 (0)
  -->
 <!-- Title: CMakeDeps Pages: 1 -->
 <svg width="1075pt" height="614pt"
diff --git a/cmake/doc/docker.svg b/cmake/doc/docker.svg
index 0c46418f5d..221de3d4a1 100644
--- a/cmake/doc/docker.svg
+++ b/cmake/doc/docker.svg
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
  "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
-<!-- Generated by graphviz version 2.42.3 (0)
+<!-- Generated by graphviz version 2.44.1 (0)
  -->
 <!-- Title: DockerDeps Pages: 1 -->
 <svg width="2382pt" height="1113pt"
diff --git a/cmake/doc/generate_image.sh b/cmake/doc/generate_image.sh
index cd1743a7f1..7d125b4b01 100755
--- a/cmake/doc/generate_image.sh
+++ b/cmake/doc/generate_image.sh
@@ -1,8 +1,10 @@
-#/usr/bin/env bash
-set -ex
+#!/usr/bin/env bash
+set -euxo pipefail
 
-rm -f *.svg *.png
+# Check plantuml is in PATH
+command -v plantuml
+
+rm -f "*.svg"
 for i in *.dot; do
-  #plantuml -Tpng "$i";
   plantuml -Tsvg "$i";
 done