when the car is not serviced on time the engine oil will change color as its getting over use. it can be that something else is mixing with the oil. when the car is serviced and still this happens then you can check further for problems.
Belated Eid Mubarak to you too.
Best tires that i always drive is bridgestone. Make sure you get the temp rating A or B tires (A being better than .
Ideal tire pressure is 30 psi in front and 32 psi in rear.