Change background color on event

[Sebastian Schlegel]

Hi,

I'm currently working on a JIRA Project. In the end my goal is to change the backgrund color of the edit page of the issue as well as the background color of the issue page itsself after something is written by the user in the edit issue page. Once a button is clicked, all Backgrounds should return to their default colors

.Since I am completely new to JIRA, as a first step I would like to change the backround color of the edit issue page if the user enters a description for example.

My questions is:

Do I Need to create a plugin to do that?
I don't think its needed, tough I'm not sure.
If not, where do I find the files I need to edit?I hope my question and description makes sense to you, if not feel free to ask. 

Thanks in advance! :)

Sebastian 

[Matt Doar · Accepted solution]

For Jira Server, I would investigate this plugin 

https://marketplace.atlassian.com/apps/1210932/cute-for-jira?hosting=server&tab=overview

[Sebastian Schlegel]

Thanks, but rather than using an already existing plugin, I would like to script these functions by myself.