That you describe them as routes for the pictures makes me wish that the Sentai thing was a game like NTR Party. Then again, I'm glad it's just a cg set because hopefully that means Takeda will release it quicker.
And if Takeda ever does turn around and make a game using the Sentai characters, he'll already have all the standing and character poses ready to use.
And other than Red, we haven't seen anything of Yellow either. Yellow did briefly appear next to Pink in the prologue for the Milf's scenario, but Takeda hasn't shown anything of her either. Blue has gotten the most attention, the Milf has scenes, Pink does have a sexy pose/costume drawn up (I think I saw that posted somewhere) but all Yellow has got is her regular clothes and Sentai outfit. We've never seen her naked poses or any slut/fetish outfits. Hopefully we'll see some stuff from her soon.