Solaris shows as Linux
Solaris uses GRUB, a boot loader for multiple operating systems that is the de-facto standard on Linux as well. rEFIt has no way to detect which operating systems you have configured in GRUB; there could even be multiple operating systems on different partitions or disks. All rEFIt can detect is the presence of GRUB, and it assumes that means you have Linux installed.
You can change the icon displayed in the rEFIt menu. When rEFIt detects GRUB, it will first look for an icon named “os_grub.icns”, and only use “os_linux.icns” if it can’t be found. Once you place an ICNS-format icon in /efi/refit/icons and name it “os_grub.icns”, that one will be used for your Solaris partition.
There is currently no way to configure the text displayed in the rEFIt menu (“Boot Linux from ...”), and there is no way to display the correct icon if you have both Linux and Solaris installed. This may be made configurable in the future, but will require a rewrite of significant portions of the rEFIt code base.