How to apply a color overlay in Lottie

Step 1: Prepare the Animation File

First, ensure you have a Lottie-supported animation file, typically in .json format, which can be exported from After Effects using the Bodymovin plugin.

Step 2: Load the Animation Using Lottie Library

In your application, load the animation using the Lottie library. For example, in Android, you can add a LottieAnimationView to your layout file:

xml
<com.airbnb.lottie.LottieAnimationView
    android:id="@+id/lottieAnimationView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:lottie_fileName="your_animation_file.json"/>

Step 3: Apply Color Overlay

To apply a color overlay to a Lottie animation, use the addValueCallback method. This method dynamically modifies specific animation properties, including color. For example, to change the color of a specific layer, do the following:

java
LottieAnimationView animationView = findViewById(R.id.lottieAnimationView);
KeyPath keyPath = new KeyPath("layer_name", "group_name", "fill_name");
LottieValueCallback<ColorFilter> colorFilterCallback = new LottieValueCallback<>(new SimpleColorFilter(Color.RED));
animationView.addValueCallback(keyPath, LottieProperty.COLOR_FILTER, colorFilterCallback);

In this example, the KeyPath specifies the exact path for color modification (including layer name, group name, and fill name). LottieProperty.COLOR_FILTER identifies the color filter property to modify. SimpleColorFilter is a color filter instance, set here to red.

Step 4: Test and Adjust

After applying the color overlay, run your application to observe the animation effect. Adjust the KeyPath or color values as needed to achieve the desired visual outcome.

Example

Suppose you have a simple Lottie animation with a layer named 'Circle', containing a group named 'Shape', and within that group, a fill color named 'Fill'. To change this fill color to blue, use the following code:

java
LottieAnimationView animationView = findViewById(R.id.lottieAnimationView);
KeyPath keyPath = new KeyPath("Circle", "Shape", "Fill");
LottieValueCallback<ColorFilter> colorFilterCallback = new LottieValueCallback<>(new SimpleColorFilter(Color.BLUE));
animationView.addValueCallback(keyPath, LottieProperty.COLOR_FILTER, colorFilterCallback);

This is the fundamental approach for applying color overlay in Lottie. With this technique, you can flexibly modify the animation's color at runtime, aligning it more closely with your application's theme or brand style.