I just ordered a some from Osram Lightify that you can control the colour temperature and brightness. I'm going to set them up with Home Assistant to do exactly

I just ordered a some from Osram Lightify that you can control the colour temperature and brightness. I'm going to set them up with Home Assistant to do exactly this, and at €20/bulb (for GU10) they aren't too bad (compared to the coloured Philips Hue which are €60/bulb). However as you say, it would be great if the bulbs would just do this themselves.