It wouldnt look bad matching weaves from other MFG's. On the "big ticket" items, try to stick with one MFG, and buy the little bits from other vendors, you wont have an issue. Just make sure to stick with the same "weave" style. I like the twill weave vs the plain weave. However, the plain weave may be cheaper AND more easy to match.
Im not familiar with yamaha, but isnt their factory options for any carbon pieces? Isnt it GTYP or something?