It is not necessary to have an open internet connection in order to work with DRMcalc 4.0. The delay should only be 1-2 seconds. DRMcalc is fully functional without an internet connection.
My intension behind is, to avoid screenshots in this forum that contains either no TX-RX distance calculations or wrong distances. The distance and direction from TX is quite important, especially for broadcasters.
I changed the background color, because there were some complaints about the legibility of the yellow graph on some XP desktops schemes. Now there is a maximum legibility on all desktop schemes and this is also important.
Everybody has a different taste and that is the reason why I will not make colors user changeable. Then everybody would have his own colors and it would be quite difficult to compare the results.