In the first Total Recall, there's an unimportant shot where the receptioninst at Recall is changing the color of her nails. She taps one with a stylus, and it "wipes" to a different color. (I can't remember if all of them changed, or just the ones she tapped.) The effect was flawless, and this was in 1990 - way before CGI was being used! Anyone know how they did that effect?

![enter image description here](https://i.stack.imgur.com/yQxPZ.jpg)