plugin-cas/plugin/grails-app/conf/logback.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration>

    <conversionRule conversionWord="clr" converterClass="org.springframework.boot.logging.logback.ColorConverter" />
    <conversionRule conversionWord="wex" converterClass="org.springframework.boot.logging.logback.WhitespaceThrowableProxyConverter" />

    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <withJansi>true</withJansi>
        <encoder>
            <charset>UTF-8</charset>
            <pattern>%clr(%d{yyyy-MM-dd HH:mm:ss.SSS}){faint} %clr(%5p) %clr(---){faint} %clr([%15.15t]){faint} %clr(%-40.40logger{39}){cyan} %clr(:){faint} %m%n%wex</pattern>
        </encoder>
    </appender>

    <root level="error">
        <appender-ref ref="STDOUT" />
    </root>

   <!--<logger name='grails.plugin.springsecurity' level='TRACE' />-->
   <!--<logger name='org.springframework.security' level='DEBUG' />-->
   <!--<logger name='org.hibernate.SQL' level='DEBUG' />-->
   <!--<logger name='org.hibernate.type.descriptor.sql.BasicBinder' level='TRACE' />-->

</configuration>