SVG graphics are part of almost every modern project, from app icons and charts to visual reports and dashboards. But what if you could adjust their colors directly from your Python code? Instead of opening each file in a graphics tool, you can automate the process in just a few lines. Whether you are designing dashboards, generating reports, or customizing app icons, changing SVG colors with Python can save you plenty of time. With Aspose.SVG for Python, you can easily load an SVG, modify its fill colors, and save the updated version with precision and control. In this guide, we will walk you through how to change the SVG fill color in Python.

What Is SVG Fill Color?

SVG (Scalable Vector Graphics) is an XML-based image format that scales without losing quality. Each shape, such as <circle>, <rect>, or <path> can have a fill attribute defining its internal color.

For example:

<rect width="100" height="50" fill="blue" />

Changing fill="blue" to fill="red" turns the rectangle red instantly.

Simple for one shape, but if you are working with hundreds of SVGs or generating visual reports dynamically, doing this manually isn’t scalable. That’s where Python automation comes in.

Why Change SVG Fill Color in Python?

There are many real-world cases for programmatically editing SVG fill colors:

  • Dynamic data visualization: Apply custom color palettes to charts or dashboards.
  • Brand consistency: Automatically use brand colors in generated graphics.
  • Light/Dark themes: Recolor UI icons to match app themes.
  • Automation: Update multiple SVGs without opening a design tool.

Instead of using Inkscape or Illustrator, let Python handle it fast, consistently, and fully automated.

With Aspose.SVG for Python, you can parse, edit, and export SVGs effortlessly without any third-party dependencies.

Install Aspose.SVG for Python

Install the library from PyPI:

pip install aspose-svg-net

Note: You may also download Aspose.SVG for Python from the releases.

Then import it into your project:

import aspose.svg as svg

Change SVG Fill Color in Python

Let’s start simple. We will load an existing SVG file, change its fill color, and save the updated version.

Follow the steps below to change the SVG fill color:

  1. Load the SVG file into an SVGDocument.
  2. Access the root element.
  3. Find the element you want to recolor.
  4. Update its fill attribute.
  5. Save the updated file.

The following code sample shows how to load an existing SVG file and change its fill color:

Change SVG Fill Color in Python

Change SVG Fill Color in Python – Step by Step.

Please find below the content of the circle element of sample.svg image.

  <!-- Circle element -->
  <circle cx="60" cy="75" r="30" fill="#FF6347" stroke="#000" stroke-width="2" />

Here goes the updated content of the circle element of sample_updated.svg image.

  <!-- Circle element -->
  <circle cx="60" cy="75" r="30" fill="#0F0" stroke="#000" stroke-width="2" fill-opacity="0.3"/>

Fill an SVG Path with Python

You can also modify a specific <path> element, which is useful for icons or vector shapes.

To set the fill color of a <path> element in an existing SVG, follow these steps:

  1. Load the SVG with SVGDocument.
  2. Access the root element.
  3. Select the target <path> using query_selector().
  4. Set the fill (and optional fill-opacity).
  5. Save the result.

Below is the code snippet that demonstrates filling a path element in Python.

Fill an SVG Path using Python

Fill an SVG Path using Python.

Please find below the content of the Sample-Path.svg image.

<svg height="400" width="800" xmlns="http://www.w3.org/2000/svg">
	<g stroke="black">
		<path d="M 10 100 Q 25 10 180 100 T 250 100 T 300 100 T 390 130" stroke="red" stroke-width="3" fill="none" />
    </g>
</svg>

Please find below the content of the simple-path-updated.svg image.

<svg height="400" width="800" xmlns="http://www.w3.org/2000/svg">
	<g stroke="black">
		<path d="M 10 100 Q 25 10 180 100 T 250 100 T 300 100 T 390 130" stroke="red" stroke-width="3" fill="#0F0" fill-opacity="0.3"/>
    </g>
</svg>

Apply SVG Fill via the Style Attribute

You can also set the SVG fill color using the style attribute, just like inline CSS. Follow these steps:

  1. Load the SVG with SVGDocument(path).
  2. Access the root element.
  3. Use query_selector() to select the element.
  4. Update its style with set_attribute().
  5. Save the modified SVG.

The following code example shows how to change the SVG fill color using the style attribute:

Apply SVG Fill Using the Style Attribute in Python

Apply SVG Fill Using the Style Attribute in Python.

  <!-- Circle element -->
  <circle cx="60" cy="75" r="30" fill="#FF6347" stroke="#000" stroke-width="2" style="fill: blue;"/>

Get a Free Aspose License

To unlock full functionality and remove evaluation limits, request a free temporary license from Aspose. It lets you test every feature without restrictions.

Free Learning Resources

Here are some resources to help you explore more:

SVG Fill Color : FAQs

Q: Can Aspose.SVG handle gradients or opacity fills?

A: Yes, it supports gradients, opacity, and pattern fills, all accessible through attribute manipulation.

Q: What if my SVG uses CSS for colors?

A: You can modify the style attribute or edit the internal rules directly.

Q: Can I export modified SVGs to other formats like PNG or PDF?

A: Absolutely. Aspose.SVG can render SVGs into PNG, JPG, BMP, or PDF formats.

Q: Does it depend on external software?

A: No. Aspose.SVG runs independently. There is no need for Inkscape, Illustrator, or other tools.

Conclusion

In this article, you have learned how to change SVG fill colors in Python using Aspose.SVG for Python. It gives full control from loading and editing elements to saving and even exporting your results as PNG.

This approach gives you full control to:

  • Recolor icons and charts
  • Automate theming
  • Update vector assets dynamically

With Aspose.SVG, your code becomes your design assistant that handles repetitive edits with precision and ease.

Need help? Visit our free support forum for direct assistance from the developers.

See Also