In all my 30+ years as a Christian I've never been taught how words found in a chapter can help us find the chapter theme. It seems so clear to me that I find it hard to believe I'm the only one that has seen this...no matter...look how easy it can be to see below the obvious to unearth chapter themes.
Using Colossians 4 as an example - look at my highlights below to see if a chapter theme seems to emerge... One bible I have labels this chapter "Prayer, wisdom and personal greetings" and it is true, these things are there, but every chapter has a message and this title is not much help to understanding it. I think the overall message of this chapter is to share the word and encourage others to do the same. It's about communication, writing, speaking, making contact. I've used the KJV here for copyright issues so you may find in your own translation the message is even more clear.
Watch chapters for content that seems related in any way that would suggest a theme. The Bible communicates more than what we first observe...look deeper for the treasures!
Col 4:1 Masters, give unto your servants that which is just and equal; knowing that ye also have a Master in heaven.
Col 4:2 Continue in prayer, and watch in the same with thanksgiving;
Col 4:3 Withal praying also for us, that God would open unto us a door of utterance, to speak the mystery of Christ, for which I am also in bonds:
Col 4:4 That I may make it manifest, as I ought to speak.
Col 4:5 Walk in wisdom toward them that are without, redeeming the time.
Col 4:6 Let your speech be alway with grace, seasoned with salt, that ye may know how ye ought to answer every man.
Col 4:7 All my state shall Tychicus declare unto you, who is a beloved brother, and a faithful minister and fellowservant in the Lord:
Col 4:8 Whom I have sent unto you for the same purpose, that he might know your estate, and comfort your hearts;
Col 4:9 With Onesimus, a faithful and beloved brother, who is one of you. They shall make known unto you all things which are done here.
Col 4:10 Aristarchus my fellowprisoner saluteth you, and Marcus, sister's son to Barnabas, (touching whom ye received commandments: if he come unto you, receive him;)
Col 4:11 And Jesus, which is called Justus, who are of the circumcision. These only are my fellowworkers unto the kingdom of God, which have been a comfort unto me.
Col 4:12 Epaphras, who is one of you, a servant of Christ, saluteth you, always labouring fervently for you in prayers, that ye may stand perfect and complete in all the will of God.
Col 4:13 For I bear him record, that he hath a great zeal for you, and them that are in Laodicea, and them in Hierapolis.
Col 4:14 Luke, the beloved physician, and Demas, greet you.
Col 4:15 Salute the brethren which are in Laodicea, and Nymphas, and the church which is in his house.
Col 4:16 And when this epistle is read among you, cause that it be read also in the church of the Laodiceans; and that ye likewise read the epistle from Laodicea.
Col 4:17 And say to Archippus, Take heed to the ministry which thou hast received in the Lord, that thou fulfil it.
Col 4:18 The salutation by the hand of me Paul. Remember my bonds. Grace be with you. Amen.