[hongrui]

well it depends on what species you're referring to. pitchers of N. sp. 'Viking' does get bleached in bright light. but for raffs, amps and hookers, i find that they do usually color up better when they get more light. for these guys, you can safely expose them to full sun, provided that you keep them well watered.

frankly, i am not aware of any other species other than N. sp. 'Viking' whose pitchers bleach under light. but another possibility is that for highland neps, some of them color up better in cooler temps, meaning if you keep them under shade, the lower temps may result in better coloration of the pitchers.