This Osram Colour Changing LED lamp.

The same lamp, the same exposure settings, the same ambient lighting.
Left: Cold.
Right: Hot by previous running in full intensity white mode.

I was curious if it was just me that the orange mode looked weird (not really orange) and very dim after switching from the white mode. After cooling down (a couple of minutes in orange mode) the colour stabilised to real orange - still not very bright but not so pathetic.
The lamp in white mode (should be 9.4 Watt but who knows?) runs quite hot and the function of the electronics is probably temporarily impaired by the heat.

Heat is well-known to impair the efficiency of LEDs. More, to a different degree for different colors.

Same experience with my panasonic one. Sometimes the bulb stops responding and gets stuck in the middle of a colour transition, after using white leds for too long.

I'd probably expect more from an Osram/Ledvance lamp. Proper tests would reveal the problem. Maybe they know but don't bother. Not many people use this kind of lamps. More people probably use Philips Hue and its alternatives. But I don't like the idea of using my smartphone as a light switch.
Anyway, the lamp is priced basically like a white GLS LED, so what? The remote on/off and five level dimming is an added value even without colour modes.

Red LEDs are especially sensitive to the temperature,
Because this is a temporary effect, after stabilizing it returns to the correct color they very likely considered it as a non-issue, so did not but in the temperature compensation for it. Or it responds only to the general temperature of the thing, not directly to the LED chips.