Of course Israel is a colonial project. The Zionists themselves declared it as such. How can it be a slur? Can you explain.
You can cast the Vicious Israeli Jewish Occupiers (ViJO) as the innocent victims and the Palestinians as the hostile aggressors, but only some Israelis and a few misguided Zionist partisans in the U.S. would agree with that characterization.
The Israelis ended the dialogue when it became clear that Israel had no intention of negotiating for the establishment of a sovereign state for the non-Jews. Netanyahu's pledge that there would not be a Palestinian state made further negotiation a fruitless endeavor. (no one believed his later retraction) At this point, the only solution is a single state with Israel continuing as the Apartheid ruler or a secular democratic state for the Jews and non-Jews.
"Colonial project" is just an escalated choice of words. Generally, colonies are started under the purview of larger existing nations. When you talk about colonialism -- you don't think Israel or Pakistan or "Kurdistan"..
But --- since you are inflammatory about your approach to the issues here -- go ahead and keep using it. But be aware that you have now made the Palestinian Nationalism movement (if it exists) also a "colonial project"..
If you want -- I'll stop calling it Palestinian Nationalism and refer to it as the Palestinian Colonial Project...