just use an incident meter.

I've found that 400H goes BLUE if it's shot @ box speed. This is with both DIY c-41(with Trebla/CPAC chemicals, the same as Kodak quality-wise IME) AND pro-lab development(again, in both Kodak AND Fuji chemistry). I try and do my own c-41 now, not just to save costs, but also because I control each step, so I know that my "normal" is actually a slight push(3:30 vs 3:15(c-41's "normal" time), just a tad higher contrast)

Rating it @ 200(so a 1 stop overexposure) gave me more warmth, not just more density. I found it was easier to scan(and optically print) than those shots made @ ISO 400.
*ALL METER READINGS WERE DONE VIA INCIDENT METHOD*

In all honesty, if you really want those "pastel" colors, rate the film @ ISO 80-100. It'll wash the colors out more, and the grain will be less pronounced. At least in my experience.

here's what I've found I get my color to look SIMILAR(not exactly) when rating it @ iso 125(my personal favorite when using 400H):
http://josevillablog.com/2011/07/havana-cuba/

-Dan