我不是对整个图层用一样的颜色，我是根据arcSDE中每条数据都会有颜色

也可以的，不过我没有现成的例子，给以下接口和代码供你参考！

Dim pGeoFeatureLayer As IGeoFeatureLayer
pGeoFeatureLayer = mcMap.get_Layer(i)
Dim pUniquevalueRenderer As IUniquevalueRenderer
pUniquevalueRenderer = New UniquevalueRenderer
pUniquevalueRenderer.FieldCount = 1
pUniquevalueRenderer.Field(0) = 上色的Color字段
pQueryFilter = New QueryFilter
pQueryFilter.AddField(上色的Color字段)
pCursor = pTable.Search(pQueryFilter, True)
pNextRow = pCursor.NextRow
Do While Not pNextRow Is Nothing
pNextRowBuffer = pNextRow
codevalue = pNextRowBuffer.value(fieldNumber) '取出值
pSym = New SimpleLineSymbol
If codevalue = 1 Then
With pSym
.Color = GetRGBColor(128, 0, 128)
.Width = 3
End With
pUniquevalueRenderer.Addvalue(codevalue, codevalue, pSym)
elseif codevalue=2 then
.......
endif
pNextRow = pCursor.NextRow
loop
pGFeatureLayer.Renderer = pUniquevalueRenderer

自己根据需要改改啦！加油！