A blue sky is a good sky. It’s a reassuring sight that promises clear weather and bright days. But what does it mean when the sky turns purple?
Webkit browsers showing blue text as slightly purple
I can’t find any info on this issue in Google, because every result is about the default purple a:visited color. That is NOT the issue here. The issue is with Chrome’s default anti-aliasing, on some systems blue text shows up as blueish-purple. If I change the anti-aliasing to -webkit-font-smoothing: antialiased it keeps the correct color, but then the fonts are radically different between Chrome and Firefox. The blue color I’m using is the client’s color, so it cannot change to purple like this. I’m hoping somebody has a fix for this. Here are screenshots from tests I’ve done: EDIT: Just to clarify, this has nothing to do with the default a:visited link color. My blue color is being inherited, but Chrome’s anti-aliasing is causing the text to appear purple. Here’s an example: http://jsfiddle.net/yvjjxfqt/
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Gavin
asked Aug 14, 2015 at 19:02
Gavin Gavin
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Post all the the css properties applied on the text.
Aug 18, 2015 at 13:07
@LaurentiuL. check the edit. The color is the only CSS style. Like I mentioned before, this is not a color inheritance issue. From what I can see it’s an anti-aliasing issue. The jsfiddle I posted has the same purple text problem.
Aug 18, 2015 at 14:32
Stupid review audit ate my comment. anyway, on Windows, this looks like an interaction with ClearType, as the horizontal lines in the example have the correct colour on both browsers, while the vertical lines are strongly sub-pixel-anti-aliased on Chrome but only slightly so on Firefox. (Also if you turn ClearType off then Firefox also disables antialiasing whereas Chrome does not.)
Sep 10, 2015 at 11:14
@Neil this also happens in OSX though, but only on non-retina screens. Maybe Chrome uses their own type renderer?
How Light Waves Travel
To understand why the sky is sometimes purple, it’s helpful to first understand how light travels.
The light that is produced from the Sun is white. However, when you put it through a prism, you see all the different colored light waves in the spectrum: red, orange, yellow, green, blue, indigo, and violet.
Light travels in waves—sometimes in short, dippy ones and other times in long lines with lots of peaks. Typically, light travels in a straight line unless something gets in its way, like a prism or molecules in the atmosphere.
Gases and particles in the atmosphere scatter light, and since blue travels on shorter, smaller waves, it causes charged particles to move faster, scattering more light. So we see more blue than we do red because blue gets particles worked up more than the other colors. Our eyes are also a bit more sensitive to blue light.
Violet is always there, as well, but our eyes detect it less so than blue. So, the right conditions have to be met for purple, or violet, to be visible.
The Role of Angles
In some cases, it’s a matter of where the sun is coming in at a certain angle. Some of those colors that get blocked out by blue, like yellow, red, and orange, appear a lot during sunrises and sunsets for this reason.
“Because the sun is low on the horizon, sunlight passes through more air at sunset and sunrise than during the day, when the sun is higher in the sky,” explained Steven Ackerman, professor of meteorology at the University of Wisconsin–Madison. “More atmosphere means more molecules to scatter the violet and blue light away from your eyes. If the path is long enough, all of the blue and violet light scatters out of your line of sight. The other colors continue on their way to your eyes. This is why sunsets are often yellow, orange, and red.”
Other Factors That Cause a Purple Sky
But other factors can come into play that can jumble up the light waves and the particles even more.
According to Sarah Keith-Lucas from BBC Weather, “dust, pollution, water droplets, and cloud formations” can influence the colors of the sky, too. Occasionally, pink and purple will appear more often than red and orange. This is partially due to “the optical illusion of the pink wavelengths lighting up the base of the cloud (due to the low angle of the sun’s rays), and these pink clouds superimposed on a dark blue sky. The combination of pink and dark blue can make the sky appear a deep purple.”
In the case of Hurricane Michael and other hurricanes, water droplets, a setting sun, and low cloud cover played a part in creating a purple sky after the storms have passed. Getting those purple hues is about having just the right conditions happen at the right time.
