Press M on your keyboard to reveal Mask 1 in the Timeline. Since we want the animation to start off the right side of the composition, let's make sure and draw our path off the right side of the composition until it looks something like this. So, starting in the upper right area here, I'll click and drag down to the left and notice as I drag over the Composition panel, I'm revealing that Purple Solid 1. But before I do that, I'll position my cursor off the upper right edge of my composition and then I'll press the Comma key to zoom out because I want to make sure the mask covers all edges of this layer. Now, I can drag in the Composition panel to apply the mask. To apply a mask to this layer, we'll select the layer first, then go up to the Shape tools and I'll click and hold on my Shape tools here making sure that I'm choosing the Rectangle tool. Let's turn the Visibility on for Layer 4 to reveal our Purple Solid 1 layer. This is where I want the transition to start. And let's scrub with the Current Time Indicator in the Timeline until it reaches 0:00:03:07. So, I'll press the Spacebar to stop playback. That's where we want to create our animated colors.
![adobe after effects transitions adobe after effects transitions](https://designshack.net/wp-content/uploads/Linear-Transition-Effects-for-After-Effects.jpg)
And you can see right around three seconds, I have a hard wipe transition revealing a logo. Since the Timeline panel is active, all I have to do is press the Spacebar to preview the animation.
![adobe after effects transitions adobe after effects transitions](https://i.ytimg.com/vi/0refWK_eIgo/maxresdefault.jpg)
In this tutorial, we're going to use masks applied to layer solids to build a colorful transition. Masks are shapes that are applied to layers using the Pen tool or any of the Shape tools.