Every sunglasses listing in the country tells you the lens colour. Almost none of them tell you what it does. So most people pick on looks, which is fine, right up until you're squinting through a pale mirror lens on a 38-degree January afternoon wondering why they feel weak.
Here's the bit that clears up most of the confusion: lens colour, lens darkness and UV protection are three separate specifications. They get printed on the same tag and they have almost nothing to do with each other.
The three specs, pulled apart
UV protection is a yes or no. UV400 means the lens blocks wavelengths up to 400nm, which covers UVA and UVB. A clear lens can be UV400. A very dark lens can have no UV filtering at all, which is worse than wearing nothing, because your pupil opens up behind the tint and lets more UV through. Colour tells you nothing about this. Look for the number.
Darkness is the lens category. Under AS/NZS 1067, lenses are sorted 0 to 4 by how much visible light gets through. Category 2 sits around 18-43% transmission and is fine for daytime driving. Category 3 runs roughly 8-18% and is the workhorse for Australian daylight. Category 4 is below that, alpine and desert territory, and has to be labelled as unsuitable for driving. If you want that properly broken down, it's in Cat 2 vs Cat 3 vs Cat 4 explained.
Colour is what's left over. Category tells you how much light the lens cuts. Colour tells you which wavelengths it cuts unevenly. That's the difference between how much you see and what you see.
What each tint actually does
Grey and smoke. Neutral. Cuts all wavelengths fairly evenly, so colours come through looking like colours. Nothing gets enhanced and nothing gets distorted. It's the default across Australia for a good reason: when the problem is the sheer volume of light coming off bitumen at midday, you don't want clever, you want less.
Brown, copper and amber. These absorb more blue light than red or green. Blue scatters most in the atmosphere, which is why distance haze looks blue, and it also focuses slightly differently in your eye to longer wavelengths. Cut some of it and edges sharpen up. Real-world payoff: better read on uneven ground, more definition on grass and dirt. Real-world cost: everything shifts warm.
Rose, red and cherry. Same mechanism, pushed harder. Strongest contrast lift of the common tints, and the most colour shift with it. Best in flat, low or changeable light, which in practice means the shoulder hours, heavy cloud, and dappled shade on a trail.
Green. Close to neutral with a mild contrast lift. A middle option rather than a specialist one.
Yellow and orange. Not really sunglasses. Dawn, dusk, fog, indoor courts. They'll do nothing for you at 1pm in Perth.
Mirror coatings. Not a tint at all. A reflective layer on the front face of the lens that bounces light away before it gets in. It lowers the transmission figure and takes the sting out of overhead glare, which is why you see it on lenses built for open, bright conditions. It does not add UV protection, and it shows scratches more than a plain lens does.
Match the tint to the surface, not the sport
Sport-based advice is where this usually goes wrong, because a road runner and a trail runner have opposite problems. Go off what you're looking at instead.
Bitumen and open road, full sun. Neutral grey, Category 3. There's no contrast problem to solve. There's just too much light.
Grass, dirt, singletrack, anything uneven. A contrast tint earns its keep here. Picking a root or a rut half a step earlier is worth more than accurate colour.
Water, wet roads, sand. Polarisation is doing the work, not the colour. It's also the one feature with a genuine downside, so read when polarised lenses help and when they get in your way before you assume more is better.
Early mornings, late arvos, overcast. Fix the category first, then the colour. A Cat 3 lens at 5:45am isn't a contrast problem, it's just dark.
Snow and high alpine. Category 4, and plan for the fact that you can't drive home in them.
The honest ranking
If you're buying one pair to cover most of what you do, the order of what matters goes like this.
One, UV400. Non-negotiable, and it costs nothing to get right. Two, the right category for the hours you actually train, not the hours you imagine you train. Three, fit and coverage, because a lens that sits off your face lets low sun in under the frame and no tint fixes that. If yours move, start with running sunglasses that don't bounce. Four, colour.
Colour is a real effect. It's also the smallest of the four and by a distance the most oversold. Anyone telling you a tint will change your times is having a lend of you.
If you do end up with two pairs
The useful split isn't summer and winter. It's bright-and-open versus flat-and-low, because in Australia both of those turn up in the same week.
Bright and open wants a neutral Category 3. That's RYZE Black Out in our range: matte frame, dark grey polarised lens, no colour games. Flat and low wants a lighter category with a contrast tint, which is RYZE Nova, a cherry pink polarised lens at 24% VLT, Category 2. Both UV400, both $115, and the second pair drops the pair price to $180 at checkout.
The short version
Darkness decides how much light gets through. Colour decides which light gets through. UV400 decides whether your eyes are actually protected, and it's the only one of the three that isn't a matter of taste. Get those three sorted in that order and the tint on the box becomes what it should have been all along, which is the bit you pick because you like the look of it.