why is html (black) text on red or blue, displaying blurry on 60Hz 4K

I have done something that it should not be possible yet until HDMI 2.0, I have a 4K TV connected by HDMI to a video card (NVidia GeForce 750Ti), and the card says, I have 60Hz 4K.

Works well, except,

HTML black text on red or blue background, looks blurry. On green, it is fine.

Also, a normal picture (.jpeg), black line on red or blue background, is fine.

Anybody can clue me what is going on here? How to adjust the display, or adjust html code to get it right?

The sample HTML code is just

<body bgcolor=red>
foobar
</body>

this is blurred, but if I replace with green, it is fine.

user322908

Posted 2014-08-12T01:27:27.340

Reputation: 739

Also helps to show a picture – vol7ron – 2014-08-12T04:32:57.120

Answers

It's quite possible you're running into subpixel hinting issues.

In order to get as smooth a font as possible, modern operating systems will use a subpixel rendering algorithm to add blue and red bars to letter's pixels. This allows them to use 'sub' pixels and gain just a tiny fraction of increase in size.

See the Wikipedia page for more information.

You can test and see if this is causing your issue using the Lagom image test.

MrDoom

Posted 2014-08-12T01:27:27.340

Reputation: 550

Additionally, you can configure hinting in Windows through ClearType options. There are similar options in most other OSes. It's possible the TV uses a different pixel arrangement from a normal monitor. – Bob – 2014-08-12T03:52:43.990