How can I control with dynamism a text animation based in audio?

I have a text, and I have added a animation (Fill Color - Range Selector 1 - Star/End), and I wanted that at each word that passes Fill Color Animate stay always together with the same word that I speak on my audio narration

E.g. When I say ''Netherland'' in audio, the Fill Color are exactely in this word ''Netherland''... I Think that I could control this by keyframes (many Keyframes! Maybe if I put them line by line of text, the synchronization is accurate, because then I would have more parameters (keyframes) than just two (start and end the animation)), but I supose that with expressions would better (more automatic at least in part, I believe I can use expressions in the reference of the start and end time, for example, which is automatically based on the audio of the narration)

I have a simples expression that I created, and works very well! But it's very linear! And if I stop to breathe a little in the narration, this time difference outweighs the text, and the words that I say no longer beat over what is written, just in the end yes, there is a compensation that causes everything to end adjusted, since I put so that the animation of Fill color finishes exactly at the same time of my narration

Any idea how I can control word by word between text and voice always synchronized?

This image below shows what I have at the moment, very linear ... I need something more dynamic where I can manually adjust if necessary but that is not too much work