Create Jewlery Effect in Photoshop
Chose a good looking image with Jewlery & Open it in PhotoshopCreate a Duplicate Layer & name it Colour Replace,
Now go to Image> Adjustments> Colour Replace.
Change Situration settings from 0 to -100
Select Eyedrop Tool on opend menu (with + symbol) & click on the colour in image that which colour you want to turn into Black & White
click carefully you can also use undo shortcut CTRL+Z or Eye Drop Tool with - symbol
all are fixed? click OK.
When image is not clolurising correctley? then click OK & Duplicate the background layer (Original) Drag this layer to top