The first and second editions of Thoughts On Design (hardbacks published in 1947 and 1951 respectively) were printed in three languages (English, French, and Spanish), and their black-and-white illustrations were supplemented by eight colour plates. The third edition (a paperback published in 1970) was printed only in English, and its illustrations were all in black-and-white.
The paperback version has been reprinted as a fourth edition, with a new foreword describing Thoughts on Design as "a manifesto, a call to arms and a ringing definition of what makes good design good." Unfortunately, the colour plates from the first two editions have not been reinstated, though Rand's later book A Designer's Art (also recently reprinted) includes plenty of colour images.