Parse colors in output with ansi-color plugin.

Dockerfile

@@ -32,7 +32,7 @@ ARG TOMCAT_JRE=jre8
 FROM maven:3-jdk-8 AS builder
 
 ARG GUACAMOLE_GIT_URL=https://github.com/apache/guacamole-client.git
-ARG GUACAMOLE_VERSION=latest
+ARG GUACAMOLE_VERSION=master
 
 # Build environment variables
 ENV \

Jenkinsfile

@@ -22,19 +22,23 @@ node("docker && linux && amd64") {
 			def tomcatVersion = version[0]
 			def jreVersion = version[1]
 
+			ansiColor {
+				def image = docker.build(
+					"${dockerNamespace}/${dockerBase}:tomcat${tomcatVersion}-jre${jreVersion}",
+					"--build-arg TOMCAT_VERSION=${tomcatVersion} --build-arg JRE_VERSION=${jreVersion} .")
+			}
+			
 			def guacamoleVersion
-			def image = docker.build(
-				"${dockerNamespace}/${dockerBase}:tomcat${tomcatVersion}-jre${jreVersion}",
-				"--build-arg TOMCAT_VERSION=${tomcatVersion} --build-arg JRE_VERSION=${jreVersion} .")
-
 			image.inside("-w /tmp") {
-				sh """
-				unzip /opt/guacamole/guacamole.war META-INF/maven/org.apache.guacamole/guacamole/pom.properties
-				"""
-				guacamoleVersion = sh(
-					script: "grep -Po '(?i)^version=\\K.+\\s*\$' META-INF/maven/org.apache.guacamole/guacamole/pom.properties",
-					returnStdout: true,
-				).trim()
+				ansiColor {
+					sh """
+					unzip /opt/guacamole/guacamole.war META-INF/maven/org.apache.guacamole/guacamole/pom.properties
+					"""
+					guacamoleVersion = sh(
+						script: "grep -Po '(?i)^version=\\K.+\\s*\$' META-INF/maven/org.apache.guacamole/guacamole/pom.properties",
+						returnStdout: true,
+					).trim()
+				}
 			}
 
 			def imageTag = "${dockerNamespace}/${dockerBase}:${guacamoleVersion}-tomcat${tomcatVersion}-jre${jreVersion}"