diff --git a/_data/version.sh b/_data/version.sh
index 8fffea4..fbc267a 100755
--- a/_data/version.sh
+++ b/_data/version.sh
@@ -7,6 +7,20 @@ set -o pipefail  # Return value of a pipeline is the value of the last (rightmos
 IFS=$'\n\t'      # Set $IFS to only newline and tab.
 
 
+function black() { echo -e "\x1B[30m $1 \x1B[0m"; }
+function red()   { echo -e "\x1B[31m $1 \x1B[0m"; }
+function green() { echo -e "\x1B[32m $1 \x1B[0m"; }
+function yellow(){ echo -e "\x1B[33m $1 \x1B[0m"; }
+function blue()  { echo -e "\x1B[34m $1 \x1B[0m"; }
+function purple(){ echo -e "\x1B[35m $1 \x1B[0m"; }
+function cyan()  { echo -e "\x1B[36m $1 \x1B[0m"; }
+function white() { echo -e "\x1B[37m $1 \x1B[0m"; }
+
+if [ "$( git rev-parse --abbrev-ref HEAD )" != "master" ]; then
+  >&2 red "[ERROR] Can only create versions of <master>"
+  exit 1
+fi
+
 curr_vers=$(git describe --tags --abbrev=0 | sed 's/v//g')
 
 next_ver=$(echo "$curr_vers" | awk -F. -v OFS=. 'NF==1{print ++$NF}; NF>1{if(length($NF+1)>length($NF))$(NF-1)++; $NF=sprintf("%0*d", length($NF), ($NF+1)%(10^length($NF))); print}')