White Dutch clover is the one that's generally recommended for lawns--it is, of course, white-flowered. :-)

The only purple I can find on a search is purple prairie clover, which doesn't look right. It gets three feet tall, as opposed to Dutch clover's couple of inches.

On the up side, if you like their clover, take the seed heads off of it when the flowers fade and scatter them on your lawn. You'll get purple clover. Seed heads are continuously produced on clover plants and may be gathered from mid-season onward.

You'll only need about one ounce of seed per thousand square feet to fully establish the clover. Less will get it started and the stuff isn't real shy about seeding out all by itself!

Thanks for the follow up. I searched also and couldn't find the clover I've seen with the purple flowers. I guess I'll just go with the White Dutch. I think with the type of project I have ahead of me, mixing clover seed in with the grass seed will certainly help with coverage and nutrients (nitrogen). But do you think the clover will grow quicker than the grass seed and choke it out? I plan on using very little clover seed, as you suggested. What about watering to get the clover seed going, about the same as grass seed?

Clover's easy. A week of damp and off it goes like gangbusters. Your grass seed will take longer, but the clover won't mind. It's really very forgiving.

Fortunately, clover is also not invasive. It won't choke out your grass. The opposite is true...rich, well-fed grasses choke out clover! Even when young, the grass doesn't mind having clover friends.

Really, clover seeding with grass seeding doesn't present any special challenges. Target everything for the grass seed and the clover will be perfectly happy.

Here is a link to some strawberry clover images. Is that what you are thinking of?

Most clovers are forage and grow very tall. Dutch white and strawberry are two low growing varieties.

Not sure if you've already found what your looking for, but if not, take a look at DLF's micro-clover. Specifically selected for mixing with turfgrass. Few flowers ( so fewer bees ) and less aggressive so it tends to mix more uniformly than something like white clover. Another consideration is to check out Hobbs and Hopkins ( Protime ). They've got the very best in mixes for so-called Eco-Lawns. Good luck, PG78