Since I never had any experience with MacBooks and monitors before, will it be sharp ? How about the colors ? Saw one guy saying, that he had slightly blurry font when using this monitor. I am interested in web development and web design so that would matter to me a lot.
Yes, it should be fine. Check this thread for a recent discussion about the Mac/HDMI/blurry font issue. https://forums.macrumors.com/threads/would-the-dell-s2415h-work-fine-on-latest-mac-mini.2033288/
Hint: This issue does not always occur but if it does you should first check to see if your computer has identified the device connected by HDMI as a "TV" rather than a HD computer display.
Those are nice monitors but the ports are a little "Old School". Overall this Dell monitor delivers most of the performance and features of a more expensive Dell UltraSharp or other premium display without the cost. It can be a great deal if you don't mind the glossy screen and lack of height adjustment. The other advantage of the more expensive Dells is the ports. From what I have seen, the S2415H has one VGA port and one HDMI port. Many (or all?) of the recent premium Dell monitors have loads of modern ports available.
S2415H
1 Video Graphics Array (VGA)
1 HDMI (MHL)
U2415
2 HDMI(MHL) connector
1 Mini DisplayPort
1 DisplayPort (version 1.2)
1 DisplayPort out (MST)