Real colours
Real colours
As Jim stated, we would be able to help alot more if you attached some pictures or even the models you are working on. So we can see the problems you are talking about...
When working with colors, lighting is really important. Visualize has a "Boost" function that boost the colors.
Open Visualize
Press "View" in the top left corner.
Press "Camera Panel"
A new window will popup on your screen.
Press "Boost" and adjust the brightness till you have the nuance of yellow you need.
Yellow without "Boost"
Yellow with "Boost"
Another tip is to apply the color on part level, and then drag it into Visualize.
Wooow! That is what I am talking about! Is one is original yellow!! Awesome!! But I don't have that visualize! My SW version is 2011. This visualize option can be found in which version???
Providing examples, models, screen shots ect. are very beneficial to getting accurate, or even any responses.