I know polariod glasses are a must (for safety if nothing else) Can anyone please tell me the difference different colour lenses make.

The most popular Colour / tint for general use are grey (smoke) but the other tints (browns, Yellow) each have benefits for different light levels when fishing.

A dark Tint ideal for bright, sunny conditions
Lighter Tints Suitable for less bright and overcast conditions

I had many pairs of Polarised Glasses over the years and only ever seen a small advantage but after I got myself a pair of Maui Jims in a Lighter Amber Tint I couldn’t believe how many extra fish I spotted they were probably the only bit of expensive kit that actually increased how much I caught.

__________________
Allan
Only dead fish go with the flow.

I am convinced with glasses what works the best depends heavily on the individual. I discovered by accident that a particular color and brand of glasses work better for me in terms of seeing into the water by a factor of about two compared to all the other glasses I have. It's really that big of a difference. For me it happens to be copper lenses, but your mileage will vary.

If it's at all possible, try before you buy or buy a couple of pairs from somewhere that will let you return the ones that don't work well for you and do your own test.

Grouse

I don't do any of my fishing without them,fly,coarse even sea. Not only keeping you safe like you wrote but make a massive difference (i would say adavantage) into seeing into your surrondings and spoting features,fish, and generally becoming more like a fish
the number of times i have been walking along rivers with friends and family only to lend them my polaroids to be greated with shock at what they see.
in terms of makes i have various, you can get some very cheap (reduced specs from fishtec at the mo which would definetly be worth having as a spare or to try).
not sure about the various makes although i have a pair of fishermans friends (callcuta) and they get compared to the top spec lense in the expensive glasses. And are very resaonably priced.

Polarised shades, are avery personal thing, and as mentioned previously, differ from individual to individual.
A good rule of thumb is the following, but not infallible, just a basic starting point:-
If you river has a dark coloured rock or muddy bottom, grey or almost black, making the water appear dark in colour, the best colour glasses, would be the grey tint to match the surroundings.
If the rocks in you fishing river, are a light brown to almost glary white, then the amber tint would be better.
For sand flats, salt water fishing, the blue tint is more suitable.
So, start by looking at the conditions you fish in, and match the colour tint, as close as possible to the dominant shade of the fishing water.
The tint of the glasses, diffuses the dominant colour of the backdrop, you would think that yellow, would make a yellow background appear more yellow, but in reality, it seems to have the opposite effect, by cancelling out the frequency of that colour.
For a pair of all round tint for most conditions, I would probably go with the amber tint, as it seems to work better in most conditions.
For fishing in cloudy and rainy conditions, i almost always prefer the dark grey tint, but for sunny skies, I prefer the amber.
Salt water... blue tint, without exception.
Thats just my feeling.

According to Optilabs, who make fishing and shooting glasses:

Brown: The best ‘all-round’ tint. This is a high contrast lens, providing the best vision over a wide range of lighting conditions – from a cloudless blue sky to heavy cloud cover. It also removes virtually all horizontal glare, offering excellent penetration when looking into water.

Yellow is ultra high contrast and suitable for use in very low levels of light, such as at dusk or early dawn – or in very heavy cloud cover. Orange, is exceptionally good for shooting orange clays or against a crowded woodland background. Grey is ideal for high levels of light such as in Australia or Africa. Green is a general purpose lens but is especially good for tennis players.

I have brown lenses in my (prescription) glasses, and as I find I can see so well in them (I would highly recommend the quality of Optilab's lenses) I wear them in all light conditions, though if I could afford it I would have some yellow lenses for 'last knockings'. I've tried my friend's (shooting) over-glasses with inter-changeable lenses, and it's amazing the difference tints make.

__________________
Behold the fisherman
He riseth up early and disturbeth the whole household.
MIGHTY ARE HIS PREPARATIONS!
He goeth forth full of hope and when the day is far spent he returneth
Smelling of strong drink, and the truth is not in him

Copper for all round here in UK.Yellow/Amber indoor safety glasses for the gloaming or low light fishing dries/emergers.

Not trying to promote but just to say how important glasses can be.Being a bit of an angling nomad over the years I have collected a few pairs of glasses along the way and some years ago I picked up a pair of Ocean Waves Hatterass from USA with glass Luminator Lens and a lifetime warranty.The frames have been rebuilt once in 2005 because I beat them up pretty well.I treat these glasses like gold dust these days because they have incredible properties which change with the light and I have used them in good and bad light.Very special.

I will never forget the first time I put on a pair of "good" glasses.I was staring into the wake of a boat from the flybridge with my "polariods" on looking for action when my now good friend Captain Efren passed me his glasses to try which then were Costa Del Mar Eliminators.It was like watching AVatar for the first time Another life changing experience

Best JP

Just a head's up that I have just agreed a deal with Polaroid to sponsor our (nearly) world famous caption competition on the forums and Fishing Magic from June to December this year so you will be in with a chance to win a pair of true Polaroid fishing sunglasses from next month on.

I tend to favour amber lenses for my own fishing but would like to have some yellow ones too for low light one of these days - I need prescription lenses which does add to the cost from the major well-known brands who offer Rx services unfortunately.