Ugly coarse grass in lawn
The lighter wide bladed patches could be a number of grassy weeds; therefore, I would use non-selective control.
Non-selective control means killing both the weed and the desired turf that shares space with the weeds. A common non-selective product is glyphosate, or Round-up. Keep in mind application of this product will leave a dead spot in your lawn. Beginning applications in the spring, when the weed is actively growing. I would spray the Round-up, wait 2-weeks then spraying again. Three days after the last Round-up application, scalp the area then sod or seed new turf into the dead spots.
Always sod or reseed after this process or weeds will return from the available weed seed bank. The following link provided by the Penn State University provides information on general steps in turfgrass establishment…
http://plantscience.psu.edu/research/centers/turf/extension/factsheets/establishment Steps 6 – 12 are important to your particular circumstance.
You can also take a piece of clean plastic and pin that over the weedy area. Again, begin this process in the spring. Leave the plastic over the weedy area until everything is dead, transitioned from green to white, and then white to brown (anything still green can grow back). Similar to the Round-up process, be prepared to seed new turf into this area.