That looks like one of the forage types of tall fescue. K31 is one of the most common types of those. If you're not happy with it (because it is coarse bladed and light in color, etc) you can replace it. That will involve several renovation steps including killing your existing turf (begin in mid august) and overseeding 2-3 weeks later with an improved turf type tall fescue variety or blend. You may also choose ky bluegrass which is the cadillac of grasses but not all that commonly used on the shore areas.

Thanks a lot for all the responses. I have purchased the rye grass seed and I will overseed it very soon. I am concerned about weakening the existing grass, but I just have to try and see this year and decide whether it is better to have the bermuda weakened or to put up with brown grass half of the year. :) Anyway, before I go ahead, I have some final questions in my mind: #1 Here is the current state of my lawn. It is not completely dormant I guess, but almost. Do you think it is better to wait a bit more so that it goes completely dormant, or should I overseed it right now? The weather is expected to be around high 60's (F), max 70F during the day and mid 50's (F), minimum 53- 54 (F) during the night until the end of October. #2 The place that I purchased the seed advised me to apply the seed at a rate of 30 g. per square meters (approx. 6.5 lb per 1000 sq. feet). Is this a good amount? #3 After I overseed, I know I have to water frequently, but refrain from creating a pond on top. Here, the soil is always wet now in the mornings because of the dew, so I suppose, watering early in the morning and at night isn't necessary? Is once midday and once early in the evening with the sprinkler system sufficient? #4 I believe my current grass is not common bermuda, but a variety instead (more dense and thinner and finer looking blades). Is it possible to identify it? Here are two more closer pictures:

That looks like it's in all sun. Fescue will thrive in the sun, like most any other grass. Does your home lawn get the same level of sun exposure? Mine sure doesn't. Trees, shrubs, cars, fences, my house, my neighbors houses, etc. all cast shadows. All that being said, when I first moved into my home, the backyard was nothing but dirt and dog poop thanks to the former owners three 90-120 lb dogs. Even crabgrass wasn't growing back there. I didn't know anything about lawns at the time, but I sure wanted a lawn back there. I planted Pennington's Kentucky 31, and it came up looking absolutely wonderful. KY-31 is, btw, dog approved: Sadly, it proved to be very prone to disease. I think brown patch or something else got it and wiped out about 1/3 to 1/2 of the lawn. Moreover, the seed was filled with tons of orchardgrass. Where the KY-31 died, the orchardgrass remained. I've since overseeded improved of TTTF (as well as some KBG and PRG) in there for the past two seasons, but nothing has ever coming close to looking as lush as that KY-31. Now I'm faced with renovating the backyard next season. Too many different types of grass going in back there and it's driving my OCD nuts. I'm actually strongly considering doing a KY-31 renovation...

PA actually sprouts in fall, winters over easily, and can make it through summer if summers are easy (in New York, they often are. Here in Pennsylvania, frequently. Further south or harsher sections of Zone 7A, not so much). The deepest greens there in the front of the shot look like a rough fescue offhand. And in this shot, some of the lime greens are definitely a fescue and won't be killed by the Tenacity; they're not PA. (I have a vast problem identifying grasses even on my ginormous monitor; my vision is terrible and usually leave the issue to others; I jumped to a conclusion I probably shouldn't've due to the chartreuse color above). They're simply not very well-matched seed, or it hasn't matured in well enough yet to color match, or there's a resource mismatch at this point. The first seems unlikely. Even the poorest seed matches better than this. That a November/December planted lawn looks bad is not at all surprising; some of that seed didn't sprout until April if it sprouted at all. The lawn should have been planted in August or September. And of them all, fescues are the ones that will play Johnny Jump-Up and mature the fastest. If you find the Milo and time don't solve this issue, and the Tenacity doesn't turn this white (meaning it's not in one of the alternate Poa species like annua or trivialis), you may want to think of killing out the mess and reseeding in August. Tedious, yep. Annoying? Oh, heck yes. The only way to get a consistent, decent lawn? Alas...yes. With a new home, you needn't do it this year. Ride it a year if you want and tackle it in July of 2021 with the kill-out and reseed in August of 2021. But that's cart before horse. Let the Milo work and, if things are improving, you can even jump the gun and apply it again around June 20th if you want (with a new lawn, this is the one time you can hit it harder). Feeding well, and organically, will move things along without forcing the issue too much. I'll also give my seal of approval to Purely Organic Lawn Food at this point (10-0-2). I used it to great effect myself this year when I had to have it delivered and couldn't get Milo or soybean meal and was stuck behind glass avoiding Captain Trips. At the moment, I have about six if-then-else paths in my head about this lawn...