Coloring Shiny for Python Action Buttons with Inline CSS: Make One Red and Another Blue

Learn how to change Shiny for Python action button colors using inline CSS background-color. Simple tweaks to make buttons distinct and improve UI clarity.

When you build a Shiny for Python interface, default action buttons often look identical. If your UI needs distinct visual accents, a simple way is to change a button’s color. Here’s a concise walkthrough showing how to do it without altering the app’s logic.

Problem

You have a layout with two action buttons and want to color them differently, but the default styling keeps them the same.

from shiny.express import ui as ux

with ux.layout_columns():
    ux.input_action_button("btn_red", "Make this button red!")
    ux.input_action_button("btn_blue", "Make this button blue!")

What’s going on

By default, creating buttons like this doesn’t apply any custom color. Without extra styling, both will render using the default theme. To make one red and another blue, you need to provide inline styling to each component.

Solution

You can pass a style attribute and set the background-color for each button. This keeps the logic intact while applying a clear visual difference.

from shiny.express import ui as ux

with ux.layout_columns():
    ux.input_action_button(
        "btn_red",
        "Make this button red!",
        style="background-color: red;"
    )
    ux.input_action_button(
        "btn_blue",
        "Make this button blue!",
        style="background-color: lightblue;"
    )

Why this matters

Color can quickly communicate intent and priority in interactive apps. Distinguishing actions visually helps users identify the right control faster and reduces misclicks, especially when several buttons sit side by side.

Takeaways

If you need to change a Shiny for Python action button’s color, pass a style attribute with the desired background-color. This minimal change keeps your code readable and your UI clearer for users who need to act quickly and confidently.