Usually HKEX will post a link on the right upper corner of the Allotment result just for a day on
www.hkex.com.hk/index.htm.
However if you could not check on the allotment result on the first day then click to
http://www.hkex.com.hk/listedco/listconews/sehk/SEHK_LISTEDCO_DATETIME_TODAY.HTM which you could find the most up date infor release from different company (including the release of allotment infor) However if your infor you request is not shown on the "Lastest" then click to "Last 7 days" and check the company that you allot for.
For seeing the result for white or yellow it is release on the allotment result. For example: HUIYUAN JUICE which was released on HKEX website at "22/02/2007 08:20 01886 ", then click to "IPO Allotment Result" which will guide you to
http://www.hkex.com.hk/listedco/listconews/sehk/20070222/LTN20070222016.htm
Then click to the different link release there. It have all the allotment result. For white or yellow, you could first read the first 2-3 sentence due to that it will say whether it is white form, yellow form, or other.
Hope this infor help for your confirmation.