Okay so here are those logos below now updated a bit...

Moving towards a final design...the purple "wireless" like bars are gone....they don't really seem to have a purpose with the design. So instead I put in an airplane. I also adjusted the sized of the silhouettes. I made the coliseum smaller and the pyramids bigger. That way they are more accurate size wise in relation to all the others.
Here I've made the plane smaller. I don't know if I should go with big plane or little plane.

Also the requirements for this is a max of 3 colors. So I've got grey, lime-ish green and purple; I'm thinking 2 colors though would be more successful for the design. Only question now is lime-ish green or purple?
This is due Friday and your opinions really matter to me! THANKS!!! :D ciao! <3