It looks like your spreader is it a drop type? or broadcast?

SLOW DOWN!

You are way ahead of yourself. At least you looked for bugs first and (I hope) did not apply insecticide.

Here are the mistakes you made in order of importance.
Overseeded in March
Used fungicide
Watering too frequently
Fertilized too much (unless you used organic)
Thatched/aerated

Can you post a close up picture of the grass taken on a cloudy day or when the sun is low in the sky? What this looks like is a 100% crabgrass lawn. That is the color of crabgrass, and that is why people don't like it.

How do you get a crabgrass lawn? You seed any kind of grass seed in the spring. When you dethatch it greatly improves the chances of getting all crabgrass. The frequent watering also helps ensure the crabgrass gets a good hold. It is as simple as that. People who recommend seeding grass seed in the spring should be sentenced to mow all the crabgrass all summer for those people who follow that advice. Aerating just costs money.

For temps that low you are watering too frequently. I would still be watering about once every 3-4 weeks at that temp.

Do you know what kind of grass you are supposed to have? Could it be annual rye instead of perennial rye? Annual rye can look yellow this time of year.

Do you have a soil test which shows that you needed to apply lime? Lime, if you have too much, can bind with iron in the soil preventing the grass from getting any. Iron deficiency makes grass look yellow.

Need a close picture. If it shows you have all crabgrass, then you can fix the entire thing in the fall (August, for you). Fall is the proper time to overseed or reseed a lawn. You don't get the crabgrass problems in the fall and the grass has all winter to develop the roots for the summer heat...although it doesn't sound like you have summer heat.

If this is crabgrass, I would simply take care of it this season like it was a perfect lawn. Trying to fight with it will just frustrate you and cost you money. Fix it right in August and start to enjoy it in September. But post a close up so we can be sure.

NOW, if it is not crabgrass, then I would start using organic fertilizer. Find your local feed store and buy a 50-pound bag of rabbit food (alfalfa pellets). Apply the pellets at a rate of 20 pounds per 1,000 square feet. It does not matter if you apply too much, so don't fret about that. Just don't smother the grass. After you apply the pellets, moisten them. The next day the pellets will swell up and look like green worms. Drag your hose across them and they will fall down into the soil and go to work. It takes 3 full weeks for the greening effect, but it will be dramatic. You can reapply alfalfa any time of day, rain or shine, any day (or every day) of the year. You can't hurt it unless you bury it in alfalfa.

Thx for the response(s). I use a scotts broadcast spreader.

I always thought I didn't have crabgrass, based on the pictures I've seen of it on the net. I posted a closeup picture below. I did a soil test today, and the PH was around 7.0, so I held off on applying more lime, like the salesman I spoke to told me would fix my issues. The darker green areas seem to be growing alot quicker, which leads me to agree that my nutrients are not being spread appropriatley, however I don't know how that is.

I guess I'm getting anxious on trying to find a resolution. The lawn started off great after I laid the seed and fertilizers down. It just has now started yellowing and I'm worried. I'll swing by and grab some rabbit food and lay it down.

Another question though, if I'm going to be overseeding again in the fall, I have an area that has filled in with Po'annua. On the advice of a scotts rep, I applied a nutsedge killer to kill it, and the product actually killed that section of my lawn. The Po'annua has since grown back and filled in the areas that the original grass had been. I've been told the Po'annua will die off in the fall, but in planning for seeding, should I eliminate it before I seed, or just seed over it? Thx again

[smiling] close up means about 3 inches away from the grass. I'd like to see the individual blades of grass. If there are any seed heads on it, that might be helpful. Gotta say, though, from this altitude it does not look like crabgrass.

It could be you have simply drenched and water washed all the fertilizer right through the soil.

Nutsedge killer for poa? First I've heard of that. Thanks for posting your results. Guess now we know how good the help is from your scott's rep.