In Internet Explorer, the + and - combo also enlarges/shrinks the text. There's also a magnifying glass and a drop-down box in the lower-right corner to change the size. IE does seem to remember the changes, though I've only tested it by going to a different site and coming back - it might not remember if you close the window.
As for color, the part I have reading is the white on light blue. Using the mouse to highlight text often helps.