1 Selective colour and mask
Open your image in Photoshop and duplicate the layer, (Cmd/Ctrl+J). Then click on Select>Color Range. The cursor changes into an eyedropper, so click and hold over the yellow dress, hold Shift simultaneously and drag your cursor around the yellow. Click OK and the whole dress should be selected.
2 B&W adjustment layer
Hit Cmd/Ctrl+Shift+I to invert the selection. Click the Create New Fill or Adjustment Layer icon at the bottom of the Layers palette. Click on Black & White… and your image will be transformed to mono and yellow. Select the Brush (B) tool with white as the foreground colour and brush over any sections still not monochrome.
3 Make the logo shine
Make a new layer (Cmd/Ctrl+Shift+N) and click OK. Now use the eyedropper tool (I) to select a bright yellow on the dress. Then select the Brush tool (B) and paint over the logo, being as neat as possible. Then change the layer’s Blending Mode to Color.