Screen gets washed out under sunlight.

[sumitkl]

Screen getting washed out and color turns somewhat grey in sunlight. 

[dineshwaran]

send the pic of your xperia display.

[MarlonUk1]

Have you tried to set the brightness setting to the max when under direct sunlight?

"The sunlight legibility marks a small improvement over the Xperia Z5 and M5. It's on par with, say, LG G5, but behind some mid-range AMOLED-packing phones."

https://www.gsmarena.com/sony_xperia_x-review-1441p3.php

[sumitkl]

Screenshot does not work, I mean I even tried to record video but seems normal only I can see color getting fade in bright sunlight.

[TheShadowRunner]

So, this is a feature called "Assertive Display" by Qualcomm. 

It totally s*cks (who wants washed out display as soon as there's sun, for no actual benefit) and there's no option to disable it in Android settings. 

But, if your device is rooted you can actually turn it off.

First go to build.prop in /system/build.prop

# Assertive Display
ro.qcom.ad=1
ro.qcom.ad.calib.data=/system/etc/ad_calib.cfg

Change ro.qcom.ad=1 to ro.qcom.ad=0, save and reboot the device.

That's it, enjoy.