Change Silver Jewellery to gold

[Ofnuts]

• Sample the color in some good part with the color picker
  
• Make a selection on the area you want to cover up
  
• Create a new layer
  
• Bucket-fill the selection with the sampled color
  
• Set the layer to blend mode HSL Color, LCH Color or, if the covered part is a sufficiently neutral grya, Multiply.
  
• Adjust opacity to taste.