The new Standolux iQ Colour Check Light by Axalta coating systems is a great colour matching tool, there are 6 different light settings, low medium and high for both light types.
The 2 light types are bright clear light with a slightly blue tinge, the other is an orange light which is designed to check for Metamerism.

Metamerism

Metamerism is a term which refers to a perceived matching of two colours that do not actually match.
A colour which is Metameric may match the target colour in daylight but in certain artificial lights, it will look different.
This light can supposedly identify these Metameric colours but I am yet to come across one so I can’t verify these claims 100%.
Metameric colours are rare from my experience and mainly affect solid (non-metallic) colours especially orange, red and yellow.

Defect Inspection

The light is also handy for checking paint defects and blends while in the spray booth, especially on silver metallic blends, I personally don’t use it for this purpose very much but it is an option.

Improved Battery life

Standolux iQ battery life is amazing, I have used it every day for over 2 weeks and I’m yet to recharge it since the initial full charge I gave it, the LED lights use a lot less power than the 3M Sun Gun.

The Sun Gun usually needs a charge every day and sometimes you’d be half way through matching a colour, only to have the battery die which is quite frustrating.

Poor battery life of the 3M Sun Gun is due to the conventional globe it uses and the fan that keeps it cool consuming a lot of power.