Per your request, here is a little more explanation of how to create and use a Running Total for this process.
Right click on the Running Total Fields in Field Explorer and select New.
Give it a Name that works for you to understand..I will use "Active Count"
The field to summarize = table.color
Type of Summary = COUNT
In teh Evaluate hit the toggle button next to "Use a formula". Thia activates teh Formula button. Click on it and add your formula here. This is a formula that tells it which items to include int he count. Anytime where the formula evaluates to TRUE will be included in the count so your formula should be .... {table.ActiveField}=1
Now in the Reset click on On change of Group (this is only an option if you have a group set up in the report). Add the leve you grouped on the COLOUR field.
Now if you place this Running Total field (drag and drop from the Field Explorer) onto the Group Footer it will count only rows in that group where the active field =1.
If you did ot group on the color field then you want to make to RT fields that include another condition for counting.
I would make one called BLUE.
It is the same process but in the formula in the Evaluate section add the extra condition to look at the response in the color field...
{table.ActiveField}=1 and {table.color}="blue"
For Reset you want ot look ata ll of the records so you set it as NEVER.
Place it on the Report Footer.
Create a another one as RED and just cnage the formula to
{table.ActiveField}=1 and {table.color}="red"
FYI -Running Totals only work on Detail sections, or footers. Tehy must be placed in report section that is below the printed records that is evaluating (or on the detial section to show a change per row).
Does this answer your questions? If not please feel free to post more detailed questions. These posts are good references for others in the future.