1. Infrared Bulbs for small scale and stand-alone setups

Color lights with Infrared remotes are without any doubt the cheapest option if you want to bring some color into your home, nevertheless, it will be very hard to integrate them in a full smart concept (taking advantage of groups, routines, and voice control).

Advantages

• Very cheap options available
• Very secure (not connected to your Wifi network at all)
• One remote could control all bulbs within visual range (maybe even simultaneously)

Disadvantages

• practically impossible to integrate into a smart home concept
• you remote needs to make visual contact with the bulb (fabric or covers could block the signal)

2. Bluetooth Smart Bulbs for small scale or stand-alone setups 

There are a lot of cheap products available, which is fine to have some fun with a single light bulb, but I would strongly advise only buying hybrid bulbs (Bluetooth/Zigbee) and use Bluetooth only in very small stand-alone deployments, keeping the option open to migrating them to a hub-centric deployment. Philips Hue is a good choice to start.

• Advantages:
  • low-cost options are available if you don't mind stand-alone proprietary solutions 
  • easy to set up, mostly connecting directly to a smartphone app or smart speaker
  • doesn't require a central hub
• Disadvantages:
  • limited control distance, your smartphone (or smart assistant) need to be within reach (10m)
  • sequential message handling, which causes a visual delay when controlling multiple lights simultaneously
  • limited security/multi-user possibilities: either a single device or anyone close to the smart bulb will be able to control it

3. Wifi-enabled lights for medium-scale setups and special features

Generally, Zigbee/Z-wave devices have more reliable connectivity, nevertheless, some features can only be found on Wifi bulbs/strips. I particularly like the Lifx Z-strip, which can actually be split into multiple zones (Polychrome Technology), resulting in a rainbow-like effect.

When deploying Wifi Smart bulbs, make sure

• you choose bulbs that have cloud APIs, and can preferably be natively connected to Google/Apple/Amazon voice assistants/home automation services
• to isolate the bulbs on your Wifi network for security reasons (preferably separate SSID on the 2.4 GHz channel)  

• Advantages:
  • they can be typically controlled from anywhere in your home, or even remotely
  • more advanced features/intelligence embedded compared to Zigbee/Z-wave bulbs that depend on the protocol standards
• Disadvantages:
  • they can be a bit more tricky in setting up
  • can cause security issues in your home network, especially when they're connected to a public cloud service. 1 light bulb with an unpatched firmware can compromise all other devices on your home network.
  • Most bulbs only support the 2.4 GHz band, and even then tend to lose connection now and then, which sometimes requires to cut power in order to reconnect to the Wifi network.
  • Any change in the WLAN network can impact the functioning of the smart bulbs. Changing the WLAN SSID will give you real nightmares.
  • When deployed in large numbers, they can also consume quite some IP addresses. Contrary to ZigBee bulbs, the more Wifi bulbs you have, the higher the chance of having a bulb that has disconnected from the Wifi network. 

4. Z-wave & ZigBee light bulbs allow you to really get it right

If you are looking for a reliable, secure and scalable smart lighting solution, I would definitely choose one of these technologies, and invest in a central bridge that is integrated or could be easily connected to home/voice assistant solutions. Thanx to the protocol standard, alternative brands are already widely available and most of the time perfectly compatible, such as Sylvania, Osram, Innr, Ledvance, complementing the flagship brands such as Philips Hue.

• Advantages:
  • mesh-based network setups get stronger and even more reliable when adding more light bulbs, as they relay each other's control signals.
  • They are available in a lot of form factors, E14, E27, GU10, and even GU5.3 to accommodate 12V connections in wet environments such as bathrooms/kitchens.
  • Tend to auto-reconnect without unplugging, in the rare case of having disconnected from the bridge
  • Changes to your WLAN network only impact the bridge and does not require reconfiguring every individual bulb
• Disadvantages:
  • requires a central gateway that can have some proprietary features depending on the vendor.
  • If you only have a few lights that are far apart, sometimes you need to add a ZigBee device (bulb, switch, or plug) just to make sure the signal reaches all devices.