Most states have something in the vehicle code about red/blue lights forward facing being illegal. Now some states/counties will permit the use of blue forward facing lights if you are a member of a volunteer fire company, but I would check to see if you need to be permitted for that before installing them.
In California, or at least here in San Diego, if you are not a peace officer any lights red/blue forward facing must be covered. I worked at a shop several years ago, working on CHP cars, we had to cover the light bars up if they were equipped so not to get stopped and ticketed. The same goes when they have volunteers working for the PD and CHP. In the photos below, these are non-peace officer volunteers, who assist police but do not have arresting powers. The CHP car has clear LED's but are yellow/amber when lit.
Now your state may have different rules, so best to check with the vehicle code or just ask a LEO.
Now one way around this, is to install clear lens LED's that are red or blue when lit, I found these on Amazon:
https://www.amazon.com/DT-MOTO-Police-Vehicle-Warning/dp/B004SX5HMG
Now using them can get you in trouble unless used off-road where most of the vehicle codes don't really apply.