Xporter not working when ScriptRunner color Jira Custom fields

import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.issue.Issue
import com.atlassian.jira.issue.RendererManager
def issue = context.issue as Issue
String customfield = "customfield_11300"
def rendererManager = ComponentAccessor.getComponent(RendererManager)
def fieldLayoutItem = ComponentAccessor.getFieldLayoutManager().getFieldLayout(issue).getFieldLayoutItem(customfield)
def renderer = rendererManager.getRendererForField(fieldLayoutItem)
String value = issue.getCustomFieldValue(ComponentAccessor.getCustomFieldManager().getCustomFieldObject(customfield))
if (value == "A"){
writer.write("<script>var css = '#customfield_11300-val { background-color: yellow; color: yellow; font-weight: bold; border-bottom: 2px solid yellow; }', head = document.head || document.getElementsByTagName('head')[0], style = document.createElement('style');head.appendChild(style);style.appendChild(document.createTextNode(css));</script>")
} else if (value == "V"){
writer.write("<script>var css = '#customfield_11300-val { background-color: red; color: red; font-weight: bold; border-bottom: 2px solid red; }', head = document.head || document.getElementsByTagName('head')[0], style = document.createElement('style');head.appendChild(style);style.appendChild(document.createTextNode(css));</script>")
}