How to change the Colour of the text in the custom field whenever the automation rule runs

[Sunilkumar k]

I need to add the text and make it as red in colour whenever the condition in automation rule satisfies , if the condition in automation rule is not satisfying the i dont want any text in custom field . How to achieve it ?

[padraik]

I know this works in the description field... but not sure about which others will respect it.  

<p style="color:#FF0000";>Red text color</p>