Sudden red coloration on plants

[coline]

Have you guys seen your plants suddenly changing their color, from a typical green to absolutely red while growing with natural sunlight?
The plants on these photos have had no change at all in their environment, sunlight and temperatures almost do not change along the year and they have already one year living there. It has happened also in D. tokaiensis and D. aliciae from what I have seen.
These 2 photos have a time of about 2 months (as for the time of my previous photo) but last week the plants still had the same color green.

[maiden]

They just wanted to show you their love :-)

Sent from my Nexus 5 using Tapatalk

[Dave Evans]

I think some may change color depending on nutrient levels. They might be getting hungry

[coline]

it might be, since one of them made a flower stalk, but not all of them did

[cephfan]

That would be a really interesting study for someone. Is the increased colouration a response to falling Nitrogen levels and are the coloured leaves more inviting to prey?

Cheers,
Steve

[fredg]

Where are you geographically coline? The photo of the red colouration appears to be showing autumnal behaviour in the background.

[theplantman]

Reddish/purplish colors are sometimes tied to low phosphorus. I doubt it for most CPs, but in many crop plants a phosphorus deficiency will cause a buildup of anthocyanin pigments and thus a color change.

www.harrells.com/blog/nutrient-of-the-month-phosphorus

I actually have a feeling that daylength might play a role. I grow all my Drosera outside and over the past 2 months mine are reddening up too as we transition into longer days.

[coline]

at this time here at 10ºN we are getting about 12,5 hours of visible light. When not fed but after some time being fed I have seen they get a little red, but I have never fed these ones.
The only thing that might have happened is that a cold wave (0,5ºC less heat) came with some rain lately, but no more