Tested on 5.0.13

No styles is being applied.

You can modify the javascript for each functions, hardcoding the SEVIRTY_COLORS, but this is not expected.

createMessage(
SEVERITY_COLORS[params.event_nseverity] || 0,
params.event_date,
params.event_time,
createProblemURL(params.zabbix_url, params.trigger_id, params.event_id, params.event_source)
)