It would be kinda bizarre if L was also derived from Light.
good point! quite possible!
well, here's the translation of the 4-panel comics if you need it:
L: Summer's here... Yagami-kun... I suppose you are going to the beach or the pool with Misa?
Raito: Yeah It's summer, so it is possible
L: Misa's swimsuit should be black, right?
Raito: Ryuuga... Don't tell me... Are you thinking what I'm thinking?
L: Yagami-kun... To tell the truth i am not talking about the matter of black or white swimsuits...
Raito: I knew it! Just as I expected from you, Ryuuga! (i know this sentence sounds wierd translated like this but it'll make sense later)
Raito: If there's a chance, ususally I also hope i could see her wear white, not swimsuits
L: That's great, Yagami-kun... It's very normal for 18-year-olds
Sayu: Ah~ I'm so happy we're going to the beach!
L: Yagami-kun, Misa-san is wearing white clothes, could that mean...
Raito: Just as I except from you, Ryuuga... She's wearing white, then that could very possibly also be white. The perfect inference...
Misa: 'Cause I am wearing swimsuit today anyway, I'm not wearing that!
Sayu: Ahh--- That's our Misa-Misa! You're great!
L: Yagami-kun... It's not the point whether she's wearing or not... I am not as excited isn't the point either....
Raito: As i expected from Ryuuga... I am also thinking about this problem
SFX: Splash Splah
Misa and Sayu: Ahh Ahh
L: The swimsuit is... white.... Compared to wearing the boring underwear this is more revealing, isn't this better? ... no... this is not the point... Yagami-kun Why am I a bit angry now... Yagami kun....
Raito: I think I am starting to understand your feelings right now... really...
L: I can't surpress my curiousity any longer. Shouldn't I just ask her? "Do you wear white?"
Raito: Ryuuga... I depending on you!!
Misa: Eh... Socks... White? Yeah... I always wear them. Why do you ask?
Raito(thinking): In some other concept... it's just as i expected from Ryuuga.....
This series of 4 panel comic is kinda confusing, but i think what it meant was
Since Misa is goth, she always wears black, so Raito is wondering if Misa ever wears white underwears, whereas L is wondering if Misa ever wears white socks