We say in Spanish Ése azul no (muy) me convence..." Meaning, [I am not sure that/ that blue suits you/that blue is appropriate/ I like that blue..." Perhaps it is on the same line?
I totally agree with you. I dare say that persuasive says more in English than convincing, and that the sentence may indicate the use of blue in publicity, or to lead someone towards a particular end.
The present tense can be used as an adjective in Hebrew, like in English (convincing). For example -
Successful - מצליח from "להצליח" - to succeed
Funny - מצחיק from "להצחיק" - to make someone laugh
Advanced - מתקדם from "להתקדם" - to advance, to progress
And many many other examples.