If you've made it black & white using the hue/saturation tool through an adjustment layer in photoshop it's a non destructive edit, and the original colour values are retained. Otherwise, it's a destructive edit and the original colour values are not retained. Sorry hon.

Any program that claims to 'restore' colour is not being honest. It does not restore colour, it re-colours a photo. Generally these programs allow the user to define features and areas within a photo then specify the base shade in each area; whilst you get shading you don't get the polychromatic spectrum we are used to seeing in modern colour photography. Like when you see old black and white movies re-coloured, the colours tend to look a bit garish.

HTH hon. Oh, and I know the photo you mean. FWIW - it's stunning in b&w.