Why are you only working on Sugar 0.88 on Ubuntu 10.04?
The Ubuntu Sugar Team is still very small and inexperienced. If we split our efforts between maintaining older versions and make Sugar 0.88 on Ubuntu 10.04, neither will be very good. The installed base of people using Sugar on older versions of Ubuntu is small enough that in the long run, it is better to help them migrate to Lucid than maintain legacy code.
Why can't I move forward on the 'chose a color' page
Several people are having trouble moving forward from the chose a color page when running Sugar under VirtualBox. Please make sure that you have installed the guest additions for your guest to insure the that the Virtual Machine's resolution is high enough to run sugar correctly.
Click on Devices > Install Guest Additions.
Open the terminal (Applications > Accessories > Terminal) and type the following:
cd /media/cdrom0/ sudo ./VBoxLinuxAdditions-x86.run