Please help us help you and fill where relevant:
LimeSurvey version: [6.5.9]
Own server or LimeSurvey Cloud: Own server
Survey theme/template: vanilla
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Hello,

We upgraded our LS version to version 6 ans we have the theme incompatibility issue.

On the welcome page, we'd need to change the color of the text "This is a sample survey description. It could be quite long. But this one isn't.".

Where can we update this color please?

 

Thank you.
 

Hi,
to do things like this investigate the page with the webdevelopment tool of your browser (F12)
You see something like this (here Firefox)
 
You see that you have to change the "color" in "text-info".
And to restrict it to the survey desription you may add to your "custom.css"
In this example I also added a "font-size" and "font-style"
 

Joffm

I noticed that you MUST use the  !important  construct to change the color.  When I inspect the survey output in Chrome DevTools, I see that the Bootstrap css file uses !important on all the colors.  Is that normal?  In other platforms I've used, such as Ionic, they do not make their own colors !important so it's easier to override in your custom.css file.