Some Christians have decided not to celebrate any special days as Paul seemed to say this was the most mature way.
10 You are observing special days and months and seasons and years!
However, reading the whole context, we can know that he was concerned that people were trying to appease God by honoring special days. God died for us to make us his children and thus be unafraid. Paul does not want them to live in fear but rather live in the Father’s love.
Christmas and Easter Both Have a Place
As such, we have freedom to celebrate special days or not. Given the marketers, even materialist China sees lots of shops with Christmas decorations. This gives us opportunities to spread the Gospel as Christmas is so well known and loved. I am a little late saying that this year. Who could not like the Christmas story of the baby in the manger? I think we can have fun with our non-Christian friends with light happy non-religious Christmas songs, and that can give us opportunities to talk about the core of Christmas. See also Merry Christmas Good News.
Easter is heavy. Jesus did more than die. It was gruesome and awful and exactly what we need. So, the marketers think on it less. Even resurrection is intimidating. Jesus is so powerful resurrected. However, His love and power is so incredible that it takes our breath away. Almighty God has died for such as us. Then he defeated death. Easter is by far more important than Christmas though we must have both. If you skip Easter, then at least Jesus gave us communion to bring us back to the Cross. See also Unpopular Easter is All I Need.