Talouselämä magazine has article "The display of Jolla handset in the world's first test - a surprising result" in Finnish.

Jolla-luurin näyttö maailman ensimmäisessä testissä - yllättävä tulos
http://www.talouselama.fi/uutiset/jo...s/a2219060?s=n

Short translation of the summary:

Jolla's display reproduces colors close to the ideal precision. This is rare on the mobile front, as usually the color reproduction of tablets and smartphones is bad. Jolla's brightness, contrast and white balance, however, are only average.

The information is based on the measurements of MPC laboratory.

Edit: Some info based on the article:

Jolla reproduces sRGB color space: 101,6%
Only better smartphones are Apple iPhone 5 (104,0%) and HTC One (101,8%).
For example Nokia Lumia 920: only 84,8%

Greens are slightly supersaturated, red tones are little flat. Naked eye cannot detect them.

Jolla's white balance is weak. Normal consumer equipment has white tone of 6500 K, Jolla's white is more than 8400 K.

Jolla's brighness: less than 350 cd/m
Best smart phones: typically 400-500 cd/m
Very best: more than 600 cd/m

Jolla's contrast: 640:1 contrast ratio, only average
Good mobile LCD: minimum 1000:1
Best: up to nearly 2000:1