Your whites are off. You are getting a 'yellowed' fill in the whites on the picture of the daisy's, likely from heavy reflection of the very yellow surroundings. This should be quite simple to fix in post production, even easier if you shoot in RAW. Personally, I would not worry about color at all until post, color is infinitely modable after the fact without a loss of quality, so unless you are working on time sensitive projects, like photo-journalism, or need to crank out hundreds of wedding photo's quickly and painlessly, I simply wouldn't worry about it. Otherwise, you are going to need to be working with a custom color balance in camera, which is easy enough, and then use things like bounce light reflectors in the field (most practical with an assistant or two) which will help negate some of the colored bounced light from the surroundings. But like I said, if you aren't in a rush and if you like the shots you have here already, the colors are infinitely adjustable without losing quality, and that is where I would put my effort, so don't stress it.
also worth a note; when posting .jpg's to Canonrumors there can be alterations to the file that end up changing color vs. the actual .jpg you first uploaded.