"Yomimasu" means something that you plan on doing later, "yondeimasu" means that you're doing it right now. i.e. Watashi wa hon wo yondeimasu = I'm reading a book (right now). Gohan wo tabetara hon wo yomimasu = After I eat dinner, I'll read a book.

yomimasu= will read now or in the future. yondeimasu= is reading

Both 'Yomimasu' and 'Yondeimasu' is correct, because... => Yomimasu is the verb that means 'read' and is in present and future tense. => Yondeimasu is the verb that means 'reading' and is in the continuous tense. __________________________ There are 2 types of adjectives in Japanese, i-adjective and na-adjective. As for the colors (i.e. aka, ao etc.) they end with i-adjectives before a noun. For example, akai hon (red book), aoi sora (blue sky). BUT...sometimes both the i-adjectives and nouns are conjugated together and the 'i' is removed in that case. Like, aozora (blue sky). Sora changes to zora too. This conjugation is done for certain circumstances which you will learn as you progress with your Japanese. If you want to learn a little more about this conjugation, you can start reading from the middle of this page that start with the title 'i-adjectives'. Hope my answer was helpful and not confusing! Enjoy studying Japanese! (^_^)