Customizing the Modern UI theme colors and logo

With the Simple Theme customizer Zimlet you can change the Modern UI
appearance in a fast and easy way. Simple Theme customizer Zimlet
supports setting the primary and secondary color and the logo on Zimbra
Modern UI. You can set these settings globally or per domain.

Configuring and installing

Create a file /tmp/zimbra-zimlet-simple-theme.xml with the following

<zimletConfig name="zimbra-zimlet-simple-theme" version="0.0.1">
        <property name="primaryColor">#ff0000</property>
        <property name="secondaryColor">#fbcebd</property>
        <property name="logo">url(data:image/png;base64,iVBORw0 ... 5ErkJggg==)</property>

To set a property for a specific domain you can prepend the domain with
a hyphen (-) like this:

<property name="">#ffff00</property>

You can use a HTML color picker to find the color codes:

The Zimlet uses CSS so you can set the logo via a URL or probably better
by using a so-called data-uri:

url(data:image/png;base64,iVBORw0 ... 5ErkJggg==)

The benefits of using a data-uri is that the image data is stored on
Zimbra. So you do not rely on some URL that may become unavailable in
the future. You can create a data-uri by using or

You can see a full example of
config_template.xml at

Finally install and configure the Zimlet:

cd /tmp
wget -O /tmp/
zmzimletctl deploy
zmzimletctl configure /tmp/zimbra-zimlet-simple-theme.xml
zmprov fc all


image The default Modern UI

image Modern UI after installation
of Simple Theme customizer Zimlet.

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2 Responses to Customizing the Modern UI theme colors and logo

  1. Namu November 3, 2022 at 12:49 AM #

    Hi, I have done this and its working on some but not others could please assist

    Zimbra Modern Web App Version 4.28.1 (build b6026b291, date 20220927145259)
    Server Version 9.0.0_GA_4465 (build 20220923110020)
    Connected to server

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