Studio supports gradient colors for borders on most layers—excluding text layers.
To apply a gradient border:
In the layer panel or canvas, select a layer.
In the inspector, next to the Borders heading, click the + icon.
In the Weight text field, enter the pixel count you prefer.
In the upper-right corner of the color selector modal, click either the linear gradient icon () or the radial gradient icon ().
On the left end of the gradient scrubber, click the color stop and choose the color you want to use. Repeat for right end of the gradient scrubber.
Fine-tune your gradient by clicking and dragging the midpoint as well as the color stops on each end of the gradient scrubber. Note: To change the direction of your gradient, in the selected layer on the canvas, click and drag the midpoint and color stops on the white gradient indicator.