how to add a white color as a filter on a SKSpriteNode in Swift

Question

I have added a SKSpriteNode in the scene, and I want to add a white color on it to brighten.

let armySprite = SKSpriteNode(imageNamed: "army_img")
armySprite.position = tile.Position
scene.addChild(armySprite)
armySprite.colorBlendFactor = 1
armySprite.color = .white

However, there is nothing happened. So, how can I add a white color filter on armySprite to make it more bright?

The original img is like this:

Then, what I want is like this :

Thanks.