Problem with search feature

I have come across a problem with the drop down search feature on my home page. I have noticed it is not always displaying the products it should. I tested it with the blue necklace. I know this product is Jewellery in the price range £6 -£10 and the colour blue.
I have now put this selection into the search feature.Below is a screenshot of the results page. Nothing is being displayed even though there should be at least the blue pendant necklace being displayed.