BrightHome buying guide · Updated November 6, 2026
2700K, 3000K, 4000K or 5000K?
Choose the appearance you want before ordering a multipack.
Understand the label
The Kelvin number describes the appearance of white light. Lower numbers such as 2700K look warmer, while higher numbers such as 5000K look cooler. This is separate from lumen output. You can choose warm light with a high light output or cooler light with a low output. Treat brightness and colour as two decisions when comparing listings.
Use the room as a test
For an evening sitting area, start by comparing 2700K and 3000K. For a work surface, compare your existing light with a cooler option if you prefer a crisper appearance. These are starting points for a trial, not room requirements. Put a sample in the actual fitting and look at walls, flooring and furniture at the time you normally use the room.
Check connected spaces
Stand where two lit rooms are visible together. A kitchen and open-plan living room can feel uneven if their bulbs have noticeably different tones. Decide whether you want a shared white appearance or a deliberate difference for a task area. Save the selected Kelvin number with your replacement-bulb notes so future purchases match.
Compare beyond the colour name
Retail terms such as soft white and daylight vary. Use the numeric Kelvin specification to compare two brands. If colour matching matters, also look at the colour-rendering specification and try the bulb on the objects you care about. Keep the packaging until you have checked the result at home.
Reference for the specifications discussed above. FTC light bulb shopping guidance