By default, the Selectable property is True, so the user can select the layer if the cursor hovers the solid color. The Selectable property specifies whether the color on the layer's background is selectable. You can use the Grayscale property to show the entire layer in gray scale ( disable state). Use the Value property to specify a solid / EBN color to be applied on the layer's background. For instance, you can use Selectable property on False, to prevent selecting the layer when the user selects the portion of the layer that displays the solid color. The Selectable property of the Background object, affects all the pictures / colors being shown on the layer's background. 

The solid / EBN color is applied on the layer's background if both of the following:

• Visible property is True
• Value property is different than -1 value

are accomplished.