Norri, Lintoy/ERTL/Corgi did not have a Hunter in their line but there were Lintoy sized Hawker Hunters made by both Solido and Dinky Toys but they had fixed landing gear and were finished in camouflage.
The one series that does come to mind with this criteria was by Tekno, Danemark, as their jet aircraft had well reproduced retractable gear and were mostly all silver {The Russian Mig was all green or all red {a red one is quite rare}. Of course selling these in Hong Kong in the 1960s would be similar to importing coal to Newcastle but anything is possible.

Here is the Tekno Hunter

Here is what the Tekno period jet aircraft looked liked from underneath. Some sharp eyed forum members may note that this example is not a Tekno but another maker. Anyone know the details of its production? It is rather a rare toy.

You should be able to find a good example of a Tekno Hunter today at a reasonable price as they are around. {eBay, Vectis etc....}
The quality of the Tekno diecast aircraft set the standard for the period and even served as the inspiration for the Aero Mini series of aircraft.
Hope this helps, GR