On the box of Tiko's food it has a picture of a african grey and saids for greys I tried giving the birds some and they wont eat it.

What's the brand name? Most of the time the bird it's recommended for is just there to give you an idea of what size bird the food is appropriate for. They don't make a different food for every parrot species, just a range of sizes. Cockatiel food is actually aimed at a lot of small conures and similar-sized birds in addition to cockatiels.

Its beaphar

The Details tab of this link has a nutritional analysis for the African grey food: http://www.northernparrots.com/beaphar- ... rod564234/

The one for cockatiels is here: http://www.northernparrots.com/beaphar- ... rod564232/

They're not identical to each other but they're pretty close. The additives are exactly the same. The other items are slightly different. The biggest difference is in the potassium level, but in both cases it seems reasonably close to the amount in American pellets. The Expert Panel that set the nutrition guidelines didn't make a recommendation for potassium so I can't compare it to that.

BTW the protein and fat levels in this brand are significantly higher than the amount in American brands. You can see the American levels in the charts at the bottom of http://www.littlefeatheredbuddies.com/i ... llets.html I know you were concerned about getting too much protein, but it's really the fat level that more likely to be a problem. More fat means more calories, and obesity is a major health problem for a lot of pet birds.

Looking at the ingredient list, the only difference I can see between them is that the cockatiel formula has some triticale in it (a type of grain) and the grey formula doesn't, and they list sunflower seed and sesame seed in a different order. This is a very minor difference, and I can't think of any reason why one species would need to have a difference like this. It's possible that they use the same formula for all their pellets, but they changed the formula slightly and one of these links shows the newer version and the other one shows the older version.

Ah they ate the whole bowl of Tiko's pellets I gave them.Should I continue feeding it?

I'd say go for it. sounds like it's healthy for them, if there's not a big difference between the African grey blend, and the cockatiel recipe.

The African grey recipe is almost identical to the cockatiel recipe for that brand. It'll provide the same benefits, so if they're willing to eat it there's no reason that you shouldn't give it to them and every reason that you should. This will certainly solve the problem of not being able to get the cockatiel/lovebird size.

Is there some kind of choking hazard, with larger sized pellets for smaller birds, or is it just more of a "smaller pellet = more likely eaten by smaller bird" kind of deal?

Well they would chew it up before eating it.