Cannot change colour temperature

I bought my yeelight ceiling light in May 2018 and it has been working perfectly so far.
However, few days ago, it suddently cannot adjust colour temperature by remote or apps and always remains at 6500k. It can show amber light (2700k) only in moon mode. I have reset the light already but the situation remains the same. Anything I can do or the light is out of order ?

Please have a check if battery of your remote is good enough.

Or could you change color temperature by Yeelight application?

I have already changed the battery of the remote.
But still cannot change color temperature either with the remote or yellight application.
Anyway, thank you for your reply.